gem - User contributions [en]

FG: Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics

2026-07-20T14:08:38Z

RB-SoS: /* GEM Workshop 2026 */

__TOC__
== GEM Workshop 2026 ==

We will hold the following sessions at the summer workshop. In each session, we will prioritize interactive discussions to emphasize the workshop format, while endeavoring to allocate presentation opportunities to all participants, as time permits.

'''Session 1''' KiTS/RX Tuesday 10:30am
The KiTS and RX Focus Groups invite contributions to a joint session on the three-dimensional nature of magnetic reconnection and mesoscale plasma structures in the magnetotail. While reconnection is often studied using simplified two-dimensional frameworks, growing observational and modeling evidence points to a highly structured, dynamic, and inherently three-dimensional system involving multi-scale coupling and kinetic physics. Understanding how reconnection evolves across mesoscale spatial scales and how it drives energy conversion, plasma transport, and particle acceleration remains a fundamental challenge in geospace science. In addition to the spatially-confined structure of magnetic reconnection sites, mesoscale plasma flows are often associated with these regions. These mesoscale plasma flows have been suggested both as effects of reconnection and as potential drivers of reconnection.
The session will feature an invited presentation by Anusree Roy on "Statistical Characteristics of Stormtime Bursty Bulk Flows", highlighting recent advances in our understanding of mesoscale transport and dynamics associated with reconnection-driven plasma flows.
Following the invited talk, the session will consist of a series of contributed presentations (~7 minutes plus ~3 minutes for questions and discussion), allowing participation from a broad range of observational, theoretical, and modeling perspectives. We anticipate space for approximately 6-7 contributed talks and encourage submissions that stimulate discussion on our evolving understanding of magnetic reconnection and mesoscale plasma structuring in the magnetotail.

Speakers:

1. Anusree Roy (invited) "Statistical Characteristics of Stormtime Bursty Bulk Flows"

2. Harry Arnold "Overstretch Thin Current Sheets in MHD simulations"

3. Mikhail Sitnov "Reconnection onset in overstretched thin current sheets: 3-D kinetic picture"

'''Session 2''' KiTS Wednesday at 1:30pm
KiTS Session: Substorm Onset Throughout the Magnetotail
We invite the GEM community to participate in a new KiTS session focused on Substorm Onset Throughout the Magnetotail. Despite decades of study, key questions remain regarding where and how substorms begin, how onset signatures evolve throughout the magnetotail, and the roles of reconnection, current disruption, and multiscale coupling in the onset process.
This KiTS will bring together researchers from the observations, theory, and modeling communities to assess the current state of knowledge, identify outstanding questions, and develop priorities for future research. We welcome participation from scientists at all career stages who are interested in advancing our understanding of substorm onset.

Speakers:

1. Shin Ohtani "Role of reconnection in substorm onset"

2. Grant Stephens "Substorms and growth-phase reconstructions"

3. Vincent Ledvina “A Statistical Comparison of Auroral Beads Preceding Substorm and Non-Substorm Onsets”

4. Souvik Roy "Storm-Time Evolution of Magnetotail Plasma Sheet Composition Driven by Ionospheric Outflow"

5. Mikhail Sitnov "“Bumpy” cislunar magnetotail: Data-mining reconstructions and implications for first-principles modeling"

'''Session 3''' KiTS/MESO/MAC/RBSoS Thursday at 1:30pm
The KiTS, MESO, RBSoS, and MAC Focus Groups invite contributions to a joint session on the dynamics of the near-Earth edge of the magnetotail during geomagnetic storms. This session will explore how storm-time magnetotail dynamics evolve closer to Earth and their consequences for the inner magnetosphere. Topics of interest include (very) near-Earth reconnection, dipolarization, particle injections, radiation belt sources and losses, storm-time substorm activity, and the coupling of magnetotail processes to auroral and ionospheric responses. We particularly encourage talks that address the following outstanding questions:
*How close to Earth can reconnection occur during strong storms?
*How does the transition region evolve, both radially and azimuthally, under storm-time conditions?
*What controls the recovery timescale of the coupled magnetotail–inner magnetosphere system?
*What are the sources and auroral signatures of MeV electrons that are directly injected into the inner magnetosphere?
*How does near-Earth reconnection influence storm recovery and radiation-belt dynamics?
*What role does near-Earth reconnection play in driving geoeffective currents and geomagnetically induced currents (GICs)?
*What is the relationship between geomagnetic storms and auroral substorms that occur during storm-time?

Speakers:

1. Kareem Sorathia (invited) "Direct Radiation Belt Injections and Their Auroral Counterparts"

2. Bhagyashree Waghule (invited) "Linking Very Near-Earth Reconnection (VNERX) to Mid-Latitude GICs: Evidence From the 7 September 2017 Storm"

3. Mike Shumko "On the Spatial Relationship Between the Substorm Aurora and Relativistic Electron Microbursts During a Small Substorm"

4. Weiqin Sun "Low-Altitude Observations of Energetic Electron Precipitation: Insights from ELFIN, CIRBE and SAMPEX"

5. Yang Mei "Observations of Relativistic Electrons near the Open-Closed Field Line Boundary using CIRBE and POES measurements"

6. Shin Ohtani "Near-Earth plasma sheet dynamics associated with the stormtime dawnside current wedge development"

7. Christine Gabrielse "First Observation of Multiple Very-Near-EarthReconnection Events During a Single Storm Main Phase"

'''Session 4''' KiTS/MESO/MAC Friday at 1:30pm
The KiT, MESO, and MAC Focus Groups invite participation in a joint session on future observational opportunities for understanding how LEO observations can reveal magnetosphere–ionosphere coupling and its connection to magnetotail dynamics. The session will explore how emerging and upcoming missions will advance our ability to observe, quantify, and model the coupling between the magnetotail, inner magnetosphere, and auroral ionosphere during substorms and geomagnetic storms.
Invited presentations from the EZIE, SMILE, and CINEMA mission teams will highlight new measurement capabilities and anticipated science returns, followed by a community discussion on key science opportunities and observational needs for the coming decade.
Topics for discussion may include:
*How can future missions improve our understanding of the magnetotail–ionosphere connection?
*How can global imaging, LEO measurements, and in-situ observations be combined to characterize the full M-I coupling system as it dynamically evolves?
*What multi-mission observing strategies will be most effective for studying substorms and storm-time dynamics?
*What defines the substorm cycle?
*What is the topology of the magnetotail during substorm dynamics?
*What is the structure and evolution of the substorm current wedge?

== GEM Workshop 2025 ==
{| class="wikitable"
|+ KiTS 2025 (Tentative Schedule)
|-
! colspan="4" | Session 1: KiTS-RX-MESO-CEDAR session on substorm onset Part 1 - 06/23/2025 (Mon, 01:30 PM - 03:30 PM)
|-
! Order !! !! Speaker !! Title
|-
| || Introduction (10 min) || Jason Derr || ||
|-
| 1 || 1:40-2:05 || Larry Lyons || TBD
|-
| 2 || 2:05-2:30 || Jesper Gjerloev || TBD
|-
| 3 || 2:30-2:55 || Tuija Pulkkinen || TBD
|-
| 4 || 2:55-3:20 || Mikhail Sitnov || TBD
|-
| 5 || 3:20-3:30 || Discussion || TBD
|-
! colspan="4" | Session 2: KiTS-RX-MESO-CEDAR session on substorm onset Part 2 - 06/23/2025 (Mon, 04:00 PM - 06:00 PM)
|-
! Order !! !! Speaker !! Title
|-
| || Introduction (5 min) || Jason Derr || ||
|-
| 1 || 04:05-04:15 || Andy Marshall ||Pseudobreakup vs Substorm: MMs observations and MAGE simulations of two tail reconnection events
|-
| 2 || 04:15-04:25 || Harriet George ||multi-constellation analysis of bursty bulk flows and tailward jets
|-
| 3 || 04:25-04:35 || Tuija Pulkkinen||TBD
|-
| 4 || 04:35-04:45 || Katherine Davidson||substorm onset influence from polar cap flows
|-
| 5 || 04:45-04:55 || Weiqin Sun||Dynamics of energetic electron fluxes in the magnetotail on growth and expansion phases of substorm
|-
| 6 || 04:55-05:05 || Xiaojia Zhang||Relativistic elecron bursts in the substorm magnetotail
|-
| 7 || 05:05-05:15 || Vincent Ledvina||Auroral beads
|-
| 8 || 05:15-05:25 || Mikhail Sitnov||overstretched thin current sheet/DM reconsturctions
|-
| 9 || 05:25-05:35 || Christine Gabrielse||TBD
|-
| 10 || 05:35-05:45 || Yi-Hsin Liu||x-line spreading
|-
| 11 || 05:45-06:00 || Discussion||
|-
! colspan="4" | Session 3: KiTS-MESO-CEDAR Magnetotail and Ionosphere Structure and Dynamics Inferred from Low-Altitude and Ground-Based Observations - 06/27/2025 (Mon, 10:00 AM - 12:00 AM)
|-
! Order !! !! Speaker !! Title
|-
| || Introduction (5 min) || Jason Derr || ||
|-
| 1 || 10:05-10:15 || Weiqin Sun || Spectra of energetic electrons at low-altitudes: plasma sheet to outer radiation belt transition
|-
| 2 || 10:15-10:25 || Xiaojia Zhang ||Exploring Outer Radiation Belt Losses from the International Space Station
|-
| 3 || 10:25-10:35 ||Yangyang Shen ||Aurora conterpart of fast plasma flows
|-
| 4 || 10:35-10:45 || Natalia Ganushkina ||Magnetic mapping during substorm growth phase
|-
| 5 || 10:45-10:55 ||Andrei Runov ||Relativistic electrons during dipolarizations in the near-Earth PS - link to aurora and ground-based magnetic observations
|-
| 6 || 10:55-11:05 ||Sanjay Chepuri ||The Partition of Energy Flux Transport at Bursty Bulk Flows
|-
| 7 || 11:05-11:15 ||Sheng Tiang ||Auroral beads at substorm onset and auroral arcs
|-
| 8 || 11:15-11:25 || Tetsuo Motoba ||Link between auroral streamers and geosynchronous dispersionless injections
|-
| 9 || 11:25-11:35 || Shan Wang ||Trials on decoding convection from substorm processes with MLT patterns of SMU-SML indices
|-
| 10 || 11:35-11:45 || Mike Shumko || What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm?
|-
| 11 || 11:45-11:55 || Jason Derr || TBD
|-
| 12 || 11:55-12:00 || Discussion||
|-
! colspan="4" | Session 4: KiTS-COMP thin current sheets throughout the solar system - 06/27/2025 (Mon, 01:30 PM - 03:30 PM)
|-
! Order !! !! Speaker !! Title
|-
| 1 || 01:30-01:40 || Jake Montgomery ||Jupiter’s current sheet
|-
| 2 || 01:40-01:50 || Nii-Boi Quartey ||MHD Rotational Effects on Mars' Magnetotail Current Sheet
|-
| 3 || 01:50-02:00 || Xinmin Li ||Spectral Features of Magnetic Fluctuations from Inertial to Kinetic Scales in Mercury’s Magnetotail Current Sheet
|-
| 4 || 02:00-02:10 || David Tonoian ||Parametric Regimes of Thin Current Sheets in Planetary Magnetospheres and Solar Wind
|-
| 5 || 02:10-02:20 || Sergey Kamaletdinov||Kinetics of magnetotail current sheets: role of pressure agyrotropy
|-
| 6 || 02:20-02:30 || Harry Arnold || Thin Current Sheets in MHD Simulations
|-
| 7 || 02:30-02:40 || Andrei Runov ||Relativistic electrons in the lunar-distant PS - may be link to COMP
|-
| 8 || 02:40-02:50 || Anton Artemyev ||Aurora arcs and thin current sheets
|-
| 9 || 02:50-03:30 || Discussion ||
|}
== GEM Workshop 2024 ==
We will hold the following sessions at the summer workshop. In each session, we will prioritize interactive discussions to emphasize the workshop format, while endeavoring to allocate presentation opportunities to all participants, as time permits.

June 24, 2024 (10:30 pm-12:00 pm MT): Thin current sheets - their formation, location, and stability.
Invited Speakers: Tony Rogers and Xin An

June 26, 2024 (10:30 am-12:00 pm MT): Joint session with the RX FG exploring: What is the location, timing, and importance of reconnection throughout the magnetotail?
Invited Speakers: Yi-Hsin Liu, Toshi Nishimura, and Keving Genestreti

June 26, 2024 (1:30 pm-3:00 pm MT): Plasma populations within the magnetotail and their role in substorm dynamics.
Invited Speakers: Daniel Welling and Jing Liao

June 27, 2024 (1:30 pm-3:00 pm MT): Joint session with the MESO FG examining the different energization mechanisms for various plasma species in the magnetotail and their effects on the nightside transition region.
Invited Speaker: Xiantong Wang

== Full FG Proposal ==
=== Title ===
Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (KiTS)

=== Abstract ===

The magnetotail contains many non-ideal processes that affect the evolution of substorm dynamics and its consequences in the ionosphere and inner magnetosphere. However, the substorm pre- and post- onset conditions have been understudied despite their determination of the manner in which energy is stored in the magnetotail and ultimately influence the onset mechanism, location, and timing. This focus group will study plasma populations, thin current sheets, and particle energization in fast flows from the far- to mid- and inner-edge magnetotail.

=== Topic Overview ===

The Earth’s magnetotail is where magnetic field energy is stored during a substorm growth phase and finally released during the expansion phase, either through magnetic reconnection or some other kinetic instability, resulting in charged particle acceleration and plasma heating. Being less accessible in comparison with the inner Earth’s magnetosphere for monitoring with ground-based facilities and having a much more dynamic magnetic field configuration, this region is mostly investigated via in-situ spacecraft measurements and remote sensing. Ambiguity of spatial and temporal structures is an intrinsic property of such measurements, that together with mapping/projection problems in highly non-dipolar and dynamic magnetic fields complicates the investigation of the magnetotail. Thus, the optimal approach for determination of the dominant magnetotail current sheet modes and dynamical characteristics consists in combining global numerical simulations, modern theoretical/analytical approaches, and multi-spacecraft observations organized via classical statistical approaches and modern machine learning and/or data mining (ML/DM) approaches.
The magnetotail current sheet is a principally important element of the magnetosphere, where the substorm grows and its onset is finally triggered by external drivers and/or internal plasma instabilities. A several hour long substorm growth phase with clear memory effects preconditions the magnetotail and determines the location and timing of substorm onset. Plasma transport from the distant tail and ionospheric outflow can significantly alter properties of the magnetotail and cross-magnetopause plasma transport and convective plasma heating affects the magnetotail dawn-dusk asymmetry. Similar global processes significantly alter magnetotail dynamics: plasma transport by fast plasma flows may contribute to both adiabatic (controlled by magnetic field dynamics) and nonadiabatic (determined by local plasma kinetics) charged particle acceleration. All of the aforementioned processes are also influenced by ionospheric outflow of heavy ions such as oxygen and field-aligned anisotropic electron and ion populations that are frequently detected in the near-Earth and mid-tail. This group is focused on various cross-scale couplings and processes (e.g., reconnection, buoyancy, dipolarization fronts, thin current sheets, etc.) which can occur prior to substorm onset, at the onset, and throughout the expansion phase. The primary focus is on the magnetotail current sheet embedded within the plasma sheet, its formation by plasma populations of different origins and its dynamics affecting pre-onset stability and post-onset magnetotail reconfiguration associated with energy transfer and, in particular, charged particle acceleration.
The following topics are largely motivated by recent results about the principal role which non-ideal plasma processes play in substorm dynamics from pre-onset through expansion phase. Combining modern global magnetosphere models, including dynamical ionospheric feedback and test particles, ML/DM techniques of reconstructing the magnetic field configuration and plasma parameters, theory and multiple spacecraft observational datasets, we plan to address the following outstanding questions:

[1] Magnetotail plasma populations: origins and role in substorm dynamics.

● What is the role played by ionospheric outflow, transport across the flank magnetopause, and convection from the distant magnetotail in populating the near-Earth tail?

● What are the dynamics of different plasma sources before and after substorm onset?

[2] Thin current sheet dynamics (including formation, stability, and destruction).

● Which non-ideal effects due to ions (including heaving ions) and electrons play a role in thin current sheet formation?

● What determines the location and dynamics of substorm onset in the magnetotail?

● How do thin current sheets interact with mesoscale plasma sheet structures?

[3] Role of fast plasma flows in charged particle transport and acceleration.

● What is the dominant mechanism(s) of charged particle acceleration in the magnetotail, prior to injection into the inner magnetosphere?

● Are plasma kinetics (parallel electric fields, wave-particle resonant interactions, nonadiabatic dynamics) important for charged particle acceleration in the magnetotail?

=== Timeliness ===

The rapid growth in inner magnetosphere-ionosphere-thermosphere coupling capability and increasingly high-resolution global magnetosphere simulations make this focus group timely. Further, recent efforts in incorporating empirical reconstructions into first principles models resulting in so-called gray box models offer a new ability to study the magnetotail. Further, a large fleet of spacecraft monitoring the middle and near-Earth magnetotail (measurements of THEMIS, MMS, ARTEMIS, and high-latitude ERG, POES, ELFIN measurements) provide quite a unique opportunity to verify and revise our theoretical concepts of magnetotail dynamics, charged particle acceleration and transport in this key magnetosphere region. In particular, the new MMS string-of-pearls campaign will probe the magnetotail at multiple scales simultaneously shedding light on how kinetic scales couple to the global scale of the magnetosphere.
This focus group aims to collect specialists of spacecraft data analysis (including modern ML/DM techniques), theoreticians, and specialists in numerical simulations (both global and local). The focus group will take advantage of the unique current moment with multiple available datasets and well-developed simulation tools in order to address long-standing questions about magnetotail plasma populations, conditioning of the magnetosphere by plasma flows, and magnetotail current sheet characteristics and dynamics.
Relevance to Existing GEM Focus Groups

This proposed FG is strongly related to the following existing GEM FGs:

1. Magnetic Reconnection in the Age of the Heliophysics System Observatory (2018-2024): Reconnection is a crucial mechanism for substorm onset. The proposed FG will investigate the nature of the current sheet in relation to reconnection, both near Earth neutral line and distant neutral line reconnection.

2. Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (MESO) (2022-2026): The proposed focus group will investigate the origin of these mesoscale phenomena beyond the transition region of the magnetotail and the interaction of mesoscale flows with thin current sheets.

3. Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022-2026): Dipolarization events that originate beyond the night side transition region can transport and energize particles before they precipitate. R1/R2 FACs, field-aligned potential drops and ionospheric conductance conditions, often associated with this dipolarizing flux, modify cross-tail current patterns in the current sheet during substorms.

4. Comparative Planetary Magnetospheric Processes (2023-2027): While the proposed FG focuses on Earth’s magnetotail, the similarities and difference in fundamental dynamics in comparison to other magnetotails play an important role in our understanding of Earth’s magnetotail dynamics.

5. Self-Consistent Inner Magnetospheric Modeling (2020-2025): Magnetotail substorm processes such as current sheet thinning inject energetic particle distributions which feed into the inner magnetosphere, which plays its own role in the causal chain of events that constitutes a substorm.

=== Goals and Deliverables ===

Year 1: We will begin by inviting experts from the community to introduce the main topics of the FG. We will plan to hold joint sessions with the Reconnection FG.
Year 2: A GEM challenge will be proposed for this year. We will hold joint sessions with the MESO, SCIMM, and MIT FGs.
Year 3: An update and continuation of the GEM challenge will be organized. We will continue to hold joint sessions with the MESO, SCIMM and MIT FGs as well as the Comparative Magnetospheres FG.
Year 4: The GEM challenge will be completed and summarized. We will also devote a session to determining what questions remain unanswered. We will present this summary in the form of a review paper at the end of the FG.

=== Chairs ===

● Harry Arnold, Johns Hopkins Applied Physics Laboratory, harry.arnold@jhuapl.edu (Expertise - Theory and simulations of magnetic reconnection; PIC simulations; global MHD simulations; grey box modeling)

● Jason Derr, United States Military Academy at West Point, (Expertise - Global magnetospheric dynamics; ballooning-interchange instabilities; particle acceleration via parallel electric
fields)

● Akhtar Ardakani, University of New Hampshire (Expertise - Multi-spacecraft data analysis; impact of oxygen on magnetic reconnection, mesoscales, and global dynamics)

● Anton Artemyev, University of California, Los Angeles (Expertise – Spacecraft data analysis; particle acceleration; kinetic instabilities in current sheet)

=== Research Area ===

Primary: Magnetotail and Plasma Sheet (MPS), Secondary: Global System Modeling (GSM)

=== Proposed Length ===

4 years (2024-2028). The first year will be to achieve a rough consensus on the state of the proposed topics. The remaining years will be devoted to progressing on the GEM challenge.

=== Expected Activities ===

● We will borrow methods from other existing and past focus groups to encourage more interactive “GEM-Style” sessions. In particular, the notion of “Controversy Sessions” from the recent Dipolarization FG proved to be quite successful. Thus, we will conduct these sessions at least once per meeting where we introduce two opposing viewpoints led by experts in the field.

● We will issue at least one relevant GEM Challenge and devote one session per year to discussing the model results and data analysis with the goal of reaching community consensus on the dominant physics at play in our stated topics.

● We aim to prioritize early career talks during the sessions. In addition, priority will be given to early career members with regard to post-talk questions.

● Finally we will organize joint sessions with the relevant existing FGs as stated above.

FG: Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics

2026-07-16T18:46:25Z

RB-SoS: /* GEM Workshop 2026 */

__TOC__
== GEM Workshop 2026 ==

We will hold the following sessions at the summer workshop. In each session, we will prioritize interactive discussions to emphasize the workshop format, while endeavoring to allocate presentation opportunities to all participants, as time permits.

'''Session 1''' KiTS/RX Tuesday 10:30am
The KiTS and RX Focus Groups invite contributions to a joint session on the three-dimensional nature of magnetic reconnection and mesoscale plasma structures in the magnetotail. While reconnection is often studied using simplified two-dimensional frameworks, growing observational and modeling evidence points to a highly structured, dynamic, and inherently three-dimensional system involving multi-scale coupling and kinetic physics. Understanding how reconnection evolves across mesoscale spatial scales and how it drives energy conversion, plasma transport, and particle acceleration remains a fundamental challenge in geospace science. In addition to the spatially-confined structure of magnetic reconnection sites, mesoscale plasma flows are often associated with these regions. These mesoscale plasma flows have been suggested both as effects of reconnection and as potential drivers of reconnection.
The session will feature an invited presentation by Anusree Roy on "Statistical Characteristics of Stormtime Bursty Bulk Flows", highlighting recent advances in our understanding of mesoscale transport and dynamics associated with reconnection-driven plasma flows.
Following the invited talk, the session will consist of a series of contributed presentations (~7 minutes plus ~3 minutes for questions and discussion), allowing participation from a broad range of observational, theoretical, and modeling perspectives. We anticipate space for approximately 6-7 contributed talks and encourage submissions that stimulate discussion on our evolving understanding of magnetic reconnection and mesoscale plasma structuring in the magnetotail.

Speakers:

1. Anusree Roy (invited) "Statistical Characteristics of Stormtime Bursty Bulk Flows"

2. Harry Arnold "Overstretch Thin Current Sheets in MHD simulations"

3. Mikhail Sitnov "Reconnection onset in overstretched thin current sheets: 3-D kinetic picture"

'''Session 2''' KiTS Wednesday at 1:30pm
KiTS Session: Substorm Onset Throughout the Magnetotail
We invite the GEM community to participate in a new KiTS session focused on Substorm Onset Throughout the Magnetotail. Despite decades of study, key questions remain regarding where and how substorms begin, how onset signatures evolve throughout the magnetotail, and the roles of reconnection, current disruption, and multiscale coupling in the onset process.
This KiTS will bring together researchers from the observations, theory, and modeling communities to assess the current state of knowledge, identify outstanding questions, and develop priorities for future research. We welcome participation from scientists at all career stages who are interested in advancing our understanding of substorm onset.

Speakers:

1. Shin Ohtani "Role of reconnection in substorm onset"

2. Grant Stephens "Substorms and growth-phase reconstructions"

3. Vincent Ledvina “A Statistical Comparison of Auroral Beads Preceding Substorm and Non-Substorm Onsets”

4. Souvik Roy "Storm-Time Evolution of Magnetotail Plasma Sheet Composition Driven by Ionospheric Outflow"

5. Mikhail Sitnov "“Bumpy” cislunar magnetotail: Data-mining reconstructions and implications for first-principles modeling"

'''Session 3''' KiTS/MESO/MAC/RBSoS Thursday at 1:30pm
The KiTS, MESO, RBSoS, and MAC Focus Groups invite contributions to a joint session on the dynamics of the near-Earth edge of the magnetotail during geomagnetic storms. This session will explore how storm-time magnetotail dynamics evolve closer to Earth and their consequences for the inner magnetosphere. Topics of interest include (very) near-Earth reconnection, dipolarization, particle injections, radiation belt sources and losses, storm-time substorm activity, and the coupling of magnetotail processes to auroral and ionospheric responses. We particularly encourage talks that address the following outstanding questions:
*How close to Earth can reconnection occur during strong storms?
*How does the transition region evolve, both radially and azimuthally, under storm-time conditions?
*What controls the recovery timescale of the coupled magnetotail–inner magnetosphere system?
*What are the sources and auroral signatures of MeV electrons that are directly injected into the inner magnetosphere?
*How does near-Earth reconnection influence storm recovery and radiation-belt dynamics?
*What role does near-Earth reconnection play in driving geoeffective currents and geomagnetically induced currents (GICs)?
*What is the relationship between geomagnetic storms and auroral substorms that occur during storm-time?

Speakers:

1. Kareem Sorathia (invited) "Direct Radiation Belt Injections and Their Auroral Counterparts"

2. Bhagyashree Waghule (invited) "Linking Very Near-Earth Reconnection (VNERX) to Mid-Latitude GICs: Evidence From the 7 September 2017 Storm"

3. Mike Shumko "On the Spatial Relationship Between the Substorm Aurora and Relativistic Electron Microbursts During a Small Substorm"

4. Weiqin Sun "Low-Altitude Observations of Energetic Electron Precipitation: Insights from ELFIN, CIRBE and SAMPEX"

5. Yang Mei "Observations of Relativistic Electrons near the Open-Closed Field Line Boundary using CIRBE and POES measurements"

6. Shin Ohtani "Near-Earth plasma sheet dynamics associated with the stormtime dawnside current wedge development"

7. Christine Gabrielse

'''Session 4''' KiTS/MESO/MAC Friday at 1:30pm
The KiT, MESO, and MAC Focus Groups invite participation in a joint session on future observational opportunities for understanding how LEO observations can reveal magnetosphere–ionosphere coupling and its connection to magnetotail dynamics. The session will explore how emerging and upcoming missions will advance our ability to observe, quantify, and model the coupling between the magnetotail, inner magnetosphere, and auroral ionosphere during substorms and geomagnetic storms.
Invited presentations from the EZIE, SMILE, and CINEMA mission teams will highlight new measurement capabilities and anticipated science returns, followed by a community discussion on key science opportunities and observational needs for the coming decade.
Topics for discussion may include:
*How can future missions improve our understanding of the magnetotail–ionosphere connection?
*How can global imaging, LEO measurements, and in-situ observations be combined to characterize the full M-I coupling system as it dynamically evolves?
*What multi-mission observing strategies will be most effective for studying substorms and storm-time dynamics?
*What defines the substorm cycle?
*What is the topology of the magnetotail during substorm dynamics?
*What is the structure and evolution of the substorm current wedge?

== GEM Workshop 2025 ==
{| class="wikitable"
|+ KiTS 2025 (Tentative Schedule)
|-
! colspan="4" | Session 1: KiTS-RX-MESO-CEDAR session on substorm onset Part 1 - 06/23/2025 (Mon, 01:30 PM - 03:30 PM)
|-
! Order !! !! Speaker !! Title
|-
| || Introduction (10 min) || Jason Derr || ||
|-
| 1 || 1:40-2:05 || Larry Lyons || TBD
|-
| 2 || 2:05-2:30 || Jesper Gjerloev || TBD
|-
| 3 || 2:30-2:55 || Tuija Pulkkinen || TBD
|-
| 4 || 2:55-3:20 || Mikhail Sitnov || TBD
|-
| 5 || 3:20-3:30 || Discussion || TBD
|-
! colspan="4" | Session 2: KiTS-RX-MESO-CEDAR session on substorm onset Part 2 - 06/23/2025 (Mon, 04:00 PM - 06:00 PM)
|-
! Order !! !! Speaker !! Title
|-
| || Introduction (5 min) || Jason Derr || ||
|-
| 1 || 04:05-04:15 || Andy Marshall ||Pseudobreakup vs Substorm: MMs observations and MAGE simulations of two tail reconnection events
|-
| 2 || 04:15-04:25 || Harriet George ||multi-constellation analysis of bursty bulk flows and tailward jets
|-
| 3 || 04:25-04:35 || Tuija Pulkkinen||TBD
|-
| 4 || 04:35-04:45 || Katherine Davidson||substorm onset influence from polar cap flows
|-
| 5 || 04:45-04:55 || Weiqin Sun||Dynamics of energetic electron fluxes in the magnetotail on growth and expansion phases of substorm
|-
| 6 || 04:55-05:05 || Xiaojia Zhang||Relativistic elecron bursts in the substorm magnetotail
|-
| 7 || 05:05-05:15 || Vincent Ledvina||Auroral beads
|-
| 8 || 05:15-05:25 || Mikhail Sitnov||overstretched thin current sheet/DM reconsturctions
|-
| 9 || 05:25-05:35 || Christine Gabrielse||TBD
|-
| 10 || 05:35-05:45 || Yi-Hsin Liu||x-line spreading
|-
| 11 || 05:45-06:00 || Discussion||
|-
! colspan="4" | Session 3: KiTS-MESO-CEDAR Magnetotail and Ionosphere Structure and Dynamics Inferred from Low-Altitude and Ground-Based Observations - 06/27/2025 (Mon, 10:00 AM - 12:00 AM)
|-
! Order !! !! Speaker !! Title
|-
| || Introduction (5 min) || Jason Derr || ||
|-
| 1 || 10:05-10:15 || Weiqin Sun || Spectra of energetic electrons at low-altitudes: plasma sheet to outer radiation belt transition
|-
| 2 || 10:15-10:25 || Xiaojia Zhang ||Exploring Outer Radiation Belt Losses from the International Space Station
|-
| 3 || 10:25-10:35 ||Yangyang Shen ||Aurora conterpart of fast plasma flows
|-
| 4 || 10:35-10:45 || Natalia Ganushkina ||Magnetic mapping during substorm growth phase
|-
| 5 || 10:45-10:55 ||Andrei Runov ||Relativistic electrons during dipolarizations in the near-Earth PS - link to aurora and ground-based magnetic observations
|-
| 6 || 10:55-11:05 ||Sanjay Chepuri ||The Partition of Energy Flux Transport at Bursty Bulk Flows
|-
| 7 || 11:05-11:15 ||Sheng Tiang ||Auroral beads at substorm onset and auroral arcs
|-
| 8 || 11:15-11:25 || Tetsuo Motoba ||Link between auroral streamers and geosynchronous dispersionless injections
|-
| 9 || 11:25-11:35 || Shan Wang ||Trials on decoding convection from substorm processes with MLT patterns of SMU-SML indices
|-
| 10 || 11:35-11:45 || Mike Shumko || What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm?
|-
| 11 || 11:45-11:55 || Jason Derr || TBD
|-
| 12 || 11:55-12:00 || Discussion||
|-
! colspan="4" | Session 4: KiTS-COMP thin current sheets throughout the solar system - 06/27/2025 (Mon, 01:30 PM - 03:30 PM)
|-
! Order !! !! Speaker !! Title
|-
| 1 || 01:30-01:40 || Jake Montgomery ||Jupiter’s current sheet
|-
| 2 || 01:40-01:50 || Nii-Boi Quartey ||MHD Rotational Effects on Mars' Magnetotail Current Sheet
|-
| 3 || 01:50-02:00 || Xinmin Li ||Spectral Features of Magnetic Fluctuations from Inertial to Kinetic Scales in Mercury’s Magnetotail Current Sheet
|-
| 4 || 02:00-02:10 || David Tonoian ||Parametric Regimes of Thin Current Sheets in Planetary Magnetospheres and Solar Wind
|-
| 5 || 02:10-02:20 || Sergey Kamaletdinov||Kinetics of magnetotail current sheets: role of pressure agyrotropy
|-
| 6 || 02:20-02:30 || Harry Arnold || Thin Current Sheets in MHD Simulations
|-
| 7 || 02:30-02:40 || Andrei Runov ||Relativistic electrons in the lunar-distant PS - may be link to COMP
|-
| 8 || 02:40-02:50 || Anton Artemyev ||Aurora arcs and thin current sheets
|-
| 9 || 02:50-03:30 || Discussion ||
|}
== GEM Workshop 2024 ==
We will hold the following sessions at the summer workshop. In each session, we will prioritize interactive discussions to emphasize the workshop format, while endeavoring to allocate presentation opportunities to all participants, as time permits.

June 24, 2024 (10:30 pm-12:00 pm MT): Thin current sheets - their formation, location, and stability.
Invited Speakers: Tony Rogers and Xin An

June 26, 2024 (10:30 am-12:00 pm MT): Joint session with the RX FG exploring: What is the location, timing, and importance of reconnection throughout the magnetotail?
Invited Speakers: Yi-Hsin Liu, Toshi Nishimura, and Keving Genestreti

June 26, 2024 (1:30 pm-3:00 pm MT): Plasma populations within the magnetotail and their role in substorm dynamics.
Invited Speakers: Daniel Welling and Jing Liao

June 27, 2024 (1:30 pm-3:00 pm MT): Joint session with the MESO FG examining the different energization mechanisms for various plasma species in the magnetotail and their effects on the nightside transition region.
Invited Speaker: Xiantong Wang

== Full FG Proposal ==
=== Title ===
Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (KiTS)

=== Abstract ===

The magnetotail contains many non-ideal processes that affect the evolution of substorm dynamics and its consequences in the ionosphere and inner magnetosphere. However, the substorm pre- and post- onset conditions have been understudied despite their determination of the manner in which energy is stored in the magnetotail and ultimately influence the onset mechanism, location, and timing. This focus group will study plasma populations, thin current sheets, and particle energization in fast flows from the far- to mid- and inner-edge magnetotail.

=== Topic Overview ===

The Earth’s magnetotail is where magnetic field energy is stored during a substorm growth phase and finally released during the expansion phase, either through magnetic reconnection or some other kinetic instability, resulting in charged particle acceleration and plasma heating. Being less accessible in comparison with the inner Earth’s magnetosphere for monitoring with ground-based facilities and having a much more dynamic magnetic field configuration, this region is mostly investigated via in-situ spacecraft measurements and remote sensing. Ambiguity of spatial and temporal structures is an intrinsic property of such measurements, that together with mapping/projection problems in highly non-dipolar and dynamic magnetic fields complicates the investigation of the magnetotail. Thus, the optimal approach for determination of the dominant magnetotail current sheet modes and dynamical characteristics consists in combining global numerical simulations, modern theoretical/analytical approaches, and multi-spacecraft observations organized via classical statistical approaches and modern machine learning and/or data mining (ML/DM) approaches.
The magnetotail current sheet is a principally important element of the magnetosphere, where the substorm grows and its onset is finally triggered by external drivers and/or internal plasma instabilities. A several hour long substorm growth phase with clear memory effects preconditions the magnetotail and determines the location and timing of substorm onset. Plasma transport from the distant tail and ionospheric outflow can significantly alter properties of the magnetotail and cross-magnetopause plasma transport and convective plasma heating affects the magnetotail dawn-dusk asymmetry. Similar global processes significantly alter magnetotail dynamics: plasma transport by fast plasma flows may contribute to both adiabatic (controlled by magnetic field dynamics) and nonadiabatic (determined by local plasma kinetics) charged particle acceleration. All of the aforementioned processes are also influenced by ionospheric outflow of heavy ions such as oxygen and field-aligned anisotropic electron and ion populations that are frequently detected in the near-Earth and mid-tail. This group is focused on various cross-scale couplings and processes (e.g., reconnection, buoyancy, dipolarization fronts, thin current sheets, etc.) which can occur prior to substorm onset, at the onset, and throughout the expansion phase. The primary focus is on the magnetotail current sheet embedded within the plasma sheet, its formation by plasma populations of different origins and its dynamics affecting pre-onset stability and post-onset magnetotail reconfiguration associated with energy transfer and, in particular, charged particle acceleration.
The following topics are largely motivated by recent results about the principal role which non-ideal plasma processes play in substorm dynamics from pre-onset through expansion phase. Combining modern global magnetosphere models, including dynamical ionospheric feedback and test particles, ML/DM techniques of reconstructing the magnetic field configuration and plasma parameters, theory and multiple spacecraft observational datasets, we plan to address the following outstanding questions:

[1] Magnetotail plasma populations: origins and role in substorm dynamics.

● What is the role played by ionospheric outflow, transport across the flank magnetopause, and convection from the distant magnetotail in populating the near-Earth tail?

● What are the dynamics of different plasma sources before and after substorm onset?

[2] Thin current sheet dynamics (including formation, stability, and destruction).

● Which non-ideal effects due to ions (including heaving ions) and electrons play a role in thin current sheet formation?

● What determines the location and dynamics of substorm onset in the magnetotail?

● How do thin current sheets interact with mesoscale plasma sheet structures?

[3] Role of fast plasma flows in charged particle transport and acceleration.

● What is the dominant mechanism(s) of charged particle acceleration in the magnetotail, prior to injection into the inner magnetosphere?

● Are plasma kinetics (parallel electric fields, wave-particle resonant interactions, nonadiabatic dynamics) important for charged particle acceleration in the magnetotail?

=== Timeliness ===

The rapid growth in inner magnetosphere-ionosphere-thermosphere coupling capability and increasingly high-resolution global magnetosphere simulations make this focus group timely. Further, recent efforts in incorporating empirical reconstructions into first principles models resulting in so-called gray box models offer a new ability to study the magnetotail. Further, a large fleet of spacecraft monitoring the middle and near-Earth magnetotail (measurements of THEMIS, MMS, ARTEMIS, and high-latitude ERG, POES, ELFIN measurements) provide quite a unique opportunity to verify and revise our theoretical concepts of magnetotail dynamics, charged particle acceleration and transport in this key magnetosphere region. In particular, the new MMS string-of-pearls campaign will probe the magnetotail at multiple scales simultaneously shedding light on how kinetic scales couple to the global scale of the magnetosphere.
This focus group aims to collect specialists of spacecraft data analysis (including modern ML/DM techniques), theoreticians, and specialists in numerical simulations (both global and local). The focus group will take advantage of the unique current moment with multiple available datasets and well-developed simulation tools in order to address long-standing questions about magnetotail plasma populations, conditioning of the magnetosphere by plasma flows, and magnetotail current sheet characteristics and dynamics.
Relevance to Existing GEM Focus Groups

This proposed FG is strongly related to the following existing GEM FGs:

1. Magnetic Reconnection in the Age of the Heliophysics System Observatory (2018-2024): Reconnection is a crucial mechanism for substorm onset. The proposed FG will investigate the nature of the current sheet in relation to reconnection, both near Earth neutral line and distant neutral line reconnection.

2. Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (MESO) (2022-2026): The proposed focus group will investigate the origin of these mesoscale phenomena beyond the transition region of the magnetotail and the interaction of mesoscale flows with thin current sheets.

3. Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022-2026): Dipolarization events that originate beyond the night side transition region can transport and energize particles before they precipitate. R1/R2 FACs, field-aligned potential drops and ionospheric conductance conditions, often associated with this dipolarizing flux, modify cross-tail current patterns in the current sheet during substorms.

4. Comparative Planetary Magnetospheric Processes (2023-2027): While the proposed FG focuses on Earth’s magnetotail, the similarities and difference in fundamental dynamics in comparison to other magnetotails play an important role in our understanding of Earth’s magnetotail dynamics.

5. Self-Consistent Inner Magnetospheric Modeling (2020-2025): Magnetotail substorm processes such as current sheet thinning inject energetic particle distributions which feed into the inner magnetosphere, which plays its own role in the causal chain of events that constitutes a substorm.

=== Goals and Deliverables ===

Year 1: We will begin by inviting experts from the community to introduce the main topics of the FG. We will plan to hold joint sessions with the Reconnection FG.
Year 2: A GEM challenge will be proposed for this year. We will hold joint sessions with the MESO, SCIMM, and MIT FGs.
Year 3: An update and continuation of the GEM challenge will be organized. We will continue to hold joint sessions with the MESO, SCIMM and MIT FGs as well as the Comparative Magnetospheres FG.
Year 4: The GEM challenge will be completed and summarized. We will also devote a session to determining what questions remain unanswered. We will present this summary in the form of a review paper at the end of the FG.

=== Chairs ===

● Harry Arnold, Johns Hopkins Applied Physics Laboratory, harry.arnold@jhuapl.edu (Expertise - Theory and simulations of magnetic reconnection; PIC simulations; global MHD simulations; grey box modeling)

● Jason Derr, United States Military Academy at West Point, (Expertise - Global magnetospheric dynamics; ballooning-interchange instabilities; particle acceleration via parallel electric
fields)

● Akhtar Ardakani, University of New Hampshire (Expertise - Multi-spacecraft data analysis; impact of oxygen on magnetic reconnection, mesoscales, and global dynamics)

● Anton Artemyev, University of California, Los Angeles (Expertise – Spacecraft data analysis; particle acceleration; kinetic instabilities in current sheet)

=== Research Area ===

Primary: Magnetotail and Plasma Sheet (MPS), Secondary: Global System Modeling (GSM)

=== Proposed Length ===

4 years (2024-2028). The first year will be to achieve a rough consensus on the state of the proposed topics. The remaining years will be devoted to progressing on the GEM challenge.

=== Expected Activities ===

● We will borrow methods from other existing and past focus groups to encourage more interactive “GEM-Style” sessions. In particular, the notion of “Controversy Sessions” from the recent Dipolarization FG proved to be quite successful. Thus, we will conduct these sessions at least once per meeting where we introduce two opposing viewpoints led by experts in the field.

● We will issue at least one relevant GEM Challenge and devote one session per year to discussing the model results and data analysis with the goal of reaching community consensus on the dominant physics at play in our stated topics.

● We aim to prioritize early career talks during the sessions. In addition, priority will be given to early career members with regard to post-talk questions.

● Finally we will organize joint sessions with the relevant existing FGs as stated above.

FG: Radiation Belts as a System of Systems

2026-07-15T18:53:19Z

RB-SoS: /* 7/15/2024 (Wed) */

== GEM workshop 2026 ==

The RB-SoS is organising 5 sessions at the 2026 workshop; three stand-alone sessions and two joint sessions.
=== 7/13/2026 (Mon) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': Event specific dynamics and variability between events [12-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Karen Júlia Coldebella Ferreira "Competing Mechanisms of Relativistic Electron Flux Dropout and Low Flux Maintenance During a Long Duration Sheath Region: a Case Study"
|-
|2||1:50 || Man Hua "The Dominant role of the electron isotropy boundary in controlling Earth's outer radiation belt electron lifetimes"
|-
|3||2:05 || Misty Chien "Storm-Time Preconditioning and Adiabatic Transport of MeV Electrons Observed by CIRBE/REPTile-2"
|-
|4||2:20 || Kelly Cantwell "Time Evolution of Microburst Events with BARREL: X-ray Pulsations"
|-
|5||2:35 || Wesley Martin "A Multi-Platform Analysis of Solar Energetic Particles and Their Impact on Polar Cap Absorption"
|}
Remaining time for discussion.

=== 7/14/2026 (Tue) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': General contributions [5-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:37 || Xinlin Li "Radiation Belt Dynamics from a Low Earth Orbit Perspective: New Insights from CIRBE/REPTile-2"
|-
|2||1:44 || Yang Mei "Atmospheric effects controlling Earth's inner radiation belt electrons unveiled by LEO satellite measurements and simulations"
|-
|3||1:51 || Frances Staples "Statistical Characterization of Radiation Belt Electron Acceleration Timescales Using Van Allen Probes and GPS Observations"
|-
|4||1:58 || Lauren Blum "ultra-relativistic electrons in the slot region following geomagnetic storms"
|-
|5||2:05 || David Malaspina "Inferring growth and propagation of whistler-mode waves in the radiation belts using power spectral density distributions"
|-
|6||2:12 || Huayue Chen "Chorus Element Repetition: Roles of Energetic Electron Injection and Nonlinear Wave Growth"
|-
|7||2:19 || Huayue Chen "Generation of Falling-Tone Whistler-Mode Chorus Waves in the Earth’s Magnetosphere"
|-
|8||2:26 || Greg Riggs "Understanding the Role of ULF Wave Latitude Distribution in Radiation Belt Electron Radial Diffusion"
|-
|9||2:33 || Jinbei Huang "Modeling Magnetopause Shadowing of Outer Radiation Belt Electrons: From Drift-Averaged Radial Diffusion to MLT-Resolved Drift Diffusion"
|-
|10||2:40 || Zhiyang Xia "Investigate the Effect of Plasma Density Perturbation on the Hiss Wave Amplitude"
|-
|11||2:47 || Qiushuo Wang "Observations of the Latitude and Frequency Distributions of Equatorward-Propagating Chorus Waves"
|}
Remaining time for discussion.

=== 7/15/2024 (Wed) ===
*3:30 PM - 5 PM: '''RB SoS - MPEC joint session''': Radiation belt particle precipitation [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||3:30 || FG chairs: opening remarks
|-
|1||3:35 || Myeong Joon Kim "Linear Instability Parameters Controlling Chorus Wave Modulation after the Onset of Pulsating Aurora"
|-
|2||3:55 || Qianli Ma "Modeling Radiation Belt Electron Fluxes Observed by ELFIN During the November 2021 Geomagnetic Storm"
|-
|3||4:15 || Alexander Drozdov "Intrinsic Hiss Waves and Their Role in Radiation Belt Dynamics"
|-
|4||4:35 || Zhi-Gu Li "Limits of the Bounce-Averaged Approximation: Pitch-Angle Diffusion and Electron Precipitation Near the Atmospheric Loss Cone"

|}
Remaining time for discussion.

=== 7/17/2026 (Fri) ===
*10:30 AM - 12 PM: '''RB SoS - topic session''': Cross-population coupling in the inner magnetosphere [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Ziye Zhang "The Role of the Plasmasphere in the Evolution of Reversed Radiation Belt Electron Energy Spectra."
|-
|2||1:55 || Taylor Whitney Aegerter "Electromagnetic Ion Cyclotron Waves in the Initial Phase of Geomagnetic Storms"
|-
|3||2:15 || Longzhi Gan "Bouncing Packets Driven by Ducted Lightning-Generated-Whistlers: Comparison with SAMPEX Observations"
|-
|4||2:35 || Shanshan Bao "Initial Results of Two-way Coupling of SAMI3 to the Whole Geospace Model, MAGE"
|}
Remaining time for discussion.

*1:30 PM - 3 PM: '''RB SoS - KiTs - MESO - MAC joint session''': Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere
**''Please refer to the KiTs Focus Group''

== Community resources ==

We are soliciting information on radiation belt products (models, datasets, events) that are useful to the community, in line with the deliverables outlined in our focus group proposal. We aim to collate this information and make it available to the community to facilitate collaboration across the radiation belts community. Examples of products that we aim to collect are datasets / models that can be used to study radiation belt dynamics and contact information of an expert who can be contacted for assistance with that data / model, specific events that you would like to highlight to the community, empirical models related to radiation belt dynamics, etc. If you would like to contribute to this database, please fill out this form: https://docs.google.com/forms/d/e/1FAIpQLSe5OpyJcP-A8Nd6_UNMEw4ZzzjGMov7wpRS0VTeCJEK54GMZA/viewform.

A list of products is available at: https://docs.google.com/spreadsheets/d/1lgc9SX86pXty5XQSFJA-YYt1l_lqT_KnAVfHepixmzY/edit?usp=sharing (navigate the tabs below to see different types).

== VERSIM x GEM Journal Club ==

The RB-SoS focus group is collaborating with VERSIM representatives to organise a journal club, which is held online on the first Wednesday of each month. Our goal is to create a friendly and lively environment where students can learn and engage, and build their scientific confidence. Information on the journal club (including the speaker schedule and zoom information) is available at https://aurora.troja.mff.cuni.cz/versim/index_jc.html.

== Mini-GEM 2025 ==

=== Schedule ===

The RB-SoS focus group will organise one session at the 2025 mini-GEM workshop. This will be held at 13:45 - 15:15 in room 383-385.

{| class="wikitable"
!#!! Time !! Presentations
|-
|1 ||13:45 || Louis Ozeke "A new database of large amplitude EMIC waves detected by the SWARM spacecraft"
|-
|2||13:55 || Xiaofei Shi "Statistical properties of quasi-periodic electron precipitation"
|-
|3||14:05 || Hong Zhao "Ultrarelativistic electron acceleration: Are satellite observations enough to identify the leading mechanism?"
|-
|4||14:15 || Hong Zhao "Bridging the radiation belt and ring current: new insights into energetic particle deep injection"
|-
|5||14:25 || Sergei Kamaletdinov "Energetic Electron Outward Radial Transport driven by Drift-Orbit Bifurcation"
|-
|6||14:35 || Alexander Drozdov "Python tools: Rbamlib and MTH5 Electric field data in PySPEDAS"
|-
|7||14:45 || Jay Albert "Resolution of the Greg Cunningham/quasilinear theory issue"
|-
|8||14:55 || Jay Albert "A model of Lauren Blum's periodic microburst observations"
|-
|9||15:05 || FG chairs: closing remarks
|-
|}

== Joint GEM / CEDAR Workshop 2025 ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== 6/24/2024 (Tue) ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== 6/25/2024 (Wed) ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|}

Remaining time for discussion.

=== 6/26/2024 (Thu) ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== 6/27/2024 (Fri) ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Harriet George,''' Institutet för rymdfysik (IRF) / Swedish Institute for Space Physics, harriet.george@irf.se
*'''Man Hua,''' School of Earth and Space Science and Technology, Wuhan University, huaman@whu.edu.cn
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Longzhi Gan''', Center for Space Physics, Boston University, lzgan@bu.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu (former chair).

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2026-07-10T19:44:48Z

RB-SoS: /* 7/13/2026 (Mon) */

== GEM workshop 2026 ==

The RB-SoS is organising 5 sessions at the 2026 workshop; three stand-alone sessions and two joint sessions.
=== 7/13/2026 (Mon) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': Event specific dynamics and variability between events [12-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Karen Júlia Coldebella Ferreira "Competing Mechanisms of Relativistic Electron Flux Dropout and Low Flux Maintenance During a Long Duration Sheath Region: a Case Study"
|-
|2||1:50 || Man Hua "The Dominant role of the electron isotropy boundary in controlling Earth's outer radiation belt electron lifetimes"
|-
|3||2:05 || Misty Chien "Storm-Time Preconditioning and Adiabatic Transport of MeV Electrons Observed by CIRBE/REPTile-2"
|-
|4||2:20 || Kelly Cantwell "Time Evolution of Microburst Events with BARREL: X-ray Pulsations"
|-
|5||2:35 || Wesley Martin "A Multi-Platform Analysis of Solar Energetic Particles and Their Impact on Polar Cap Absorption"
|}
Remaining time for discussion.

=== 7/14/2026 (Tue) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': General contributions [5-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:37 || Xinlin Li "Radiation Belt Dynamics from a Low Earth Orbit Perspective: New Insights from CIRBE/REPTile-2"
|-
|2||1:44 || Yang Mei "Atmospheric effects controlling Earth's inner radiation belt electrons unveiled by LEO satellite measurements and simulations"
|-
|3||1:51 || Frances Staples "Statistical Characterization of Radiation Belt Electron Acceleration Timescales Using Van Allen Probes and GPS Observations"
|-
|4||1:58 || Lauren Blum "ultra-relativistic electrons in the slot region following geomagnetic storms"
|-
|5||2:05 || David Malaspina "Inferring growth and propagation of whistler-mode waves in the radiation belts using power spectral density distributions"
|-
|6||2:12 || Huayue Chen "Chorus Element Repetition: Roles of Energetic Electron Injection and Nonlinear Wave Growth"
|-
|7||2:19 || Huayue Chen "Generation of Falling-Tone Whistler-Mode Chorus Waves in the Earth’s Magnetosphere"
|-
|8||2:26 || Greg Riggs "Understanding the Role of ULF Wave Latitude Distribution in Radiation Belt Electron Radial Diffusion"
|-
|9||2:33 || Jinbei Huang "Modeling Magnetopause Shadowing of Outer Radiation Belt Electrons: From Drift-Averaged Radial Diffusion to MLT-Resolved Drift Diffusion"
|-
|10||2:40 || Zhiyang Xia "Investigate the Effect of Plasma Density Perturbation on the Hiss Wave Amplitude"
|-
|11||2:47 || Qiushuo Wang "Observations of the Latitude and Frequency Distributions of Equatorward-Propagating Chorus Waves"
|}
Remaining time for discussion.

=== 7/15/2024 (Wed) ===
*3:30 PM - 5 PM: '''RB SoS - MPEC joint session''': Radiation belt particle precipitation [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Myeong Joon Kim "Linear Instability Parameters Controlling Chorus Wave Modulation after the Onset of Pulsating Aurora"
|-
|2||1:55 || Qianli Ma "Modeling Radiation Belt Electron Fluxes Observed by ELFIN During the November 2021 Geomagnetic Storm"
|-
|3||2:15 || Alexander Drozdov "Intrinsic Hiss Waves and Their Role in Radiation Belt Dynamics"
|-
|4||2:35 || Zhi-Gu Li "Limits of the Bounce-Averaged Approximation: Pitch-Angle Diffusion and Electron Precipitation Near the Atmospheric Loss Cone"

|}
Remaining time for discussion.

=== 7/17/2026 (Fri) ===
*10:30 AM - 12 PM: '''RB SoS - topic session''': Cross-population coupling in the inner magnetosphere [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Ziye Zhang "The Role of the Plasmasphere in the Evolution of Reversed Radiation Belt Electron Energy Spectra."
|-
|2||1:55 || Taylor Whitney Aegerter "Electromagnetic Ion Cyclotron Waves in the Initial Phase of Geomagnetic Storms"
|-
|3||2:15 || Longzhi Gan "Bouncing Packets Driven by Ducted Lightning-Generated-Whistlers: Comparison with SAMPEX Observations"
|-
|4||2:35 || Shanshan Bao "Initial Results of Two-way Coupling of SAMI3 to the Whole Geospace Model, MAGE"
|}
Remaining time for discussion.

*1:30 PM - 3 PM: '''RB SoS - KiTs - MESO - MAC joint session''': Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere
**''Please refer to the KiTs Focus Group''

== Community resources ==

We are soliciting information on radiation belt products (models, datasets, events) that are useful to the community, in line with the deliverables outlined in our focus group proposal. We aim to collate this information and make it available to the community to facilitate collaboration across the radiation belts community. Examples of products that we aim to collect are datasets / models that can be used to study radiation belt dynamics and contact information of an expert who can be contacted for assistance with that data / model, specific events that you would like to highlight to the community, empirical models related to radiation belt dynamics, etc. If you would like to contribute to this database, please fill out this form: https://docs.google.com/forms/d/e/1FAIpQLSe5OpyJcP-A8Nd6_UNMEw4ZzzjGMov7wpRS0VTeCJEK54GMZA/viewform.

A list of products is available at: https://docs.google.com/spreadsheets/d/1lgc9SX86pXty5XQSFJA-YYt1l_lqT_KnAVfHepixmzY/edit?usp=sharing (navigate the tabs below to see different types).

== VERSIM x GEM Journal Club ==

The RB-SoS focus group is collaborating with VERSIM representatives to organise a journal club, which is held online on the first Wednesday of each month. Our goal is to create a friendly and lively environment where students can learn and engage, and build their scientific confidence. Information on the journal club (including the speaker schedule and zoom information) is available at https://aurora.troja.mff.cuni.cz/versim/index_jc.html.

== Mini-GEM 2025 ==

=== Schedule ===

The RB-SoS focus group will organise one session at the 2025 mini-GEM workshop. This will be held at 13:45 - 15:15 in room 383-385.

{| class="wikitable"
!#!! Time !! Presentations
|-
|1 ||13:45 || Louis Ozeke "A new database of large amplitude EMIC waves detected by the SWARM spacecraft"
|-
|2||13:55 || Xiaofei Shi "Statistical properties of quasi-periodic electron precipitation"
|-
|3||14:05 || Hong Zhao "Ultrarelativistic electron acceleration: Are satellite observations enough to identify the leading mechanism?"
|-
|4||14:15 || Hong Zhao "Bridging the radiation belt and ring current: new insights into energetic particle deep injection"
|-
|5||14:25 || Sergei Kamaletdinov "Energetic Electron Outward Radial Transport driven by Drift-Orbit Bifurcation"
|-
|6||14:35 || Alexander Drozdov "Python tools: Rbamlib and MTH5 Electric field data in PySPEDAS"
|-
|7||14:45 || Jay Albert "Resolution of the Greg Cunningham/quasilinear theory issue"
|-
|8||14:55 || Jay Albert "A model of Lauren Blum's periodic microburst observations"
|-
|9||15:05 || FG chairs: closing remarks
|-
|}

== Joint GEM / CEDAR Workshop 2025 ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== 6/24/2024 (Tue) ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== 6/25/2024 (Wed) ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|}

Remaining time for discussion.

=== 6/26/2024 (Thu) ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== 6/27/2024 (Fri) ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Harriet George,''' Institutet för rymdfysik (IRF) / Swedish Institute for Space Physics, harriet.george@irf.se
*'''Man Hua,''' School of Earth and Space Science and Technology, Wuhan University, huaman@whu.edu.cn
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Longzhi Gan''', Center for Space Physics, Boston University, lzgan@bu.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu (former chair).

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2026-07-08T17:21:38Z

RB-SoS: /* 7/14/2026 (Tue) */

== GEM workshop 2026 ==

The RB-SoS is organising 5 sessions at the 2026 workshop; three stand-alone sessions and two joint sessions.
=== 7/13/2026 (Mon) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': Event specific dynamics and variability between events [12-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Karen Júlia Coldebella Ferreira "Competing Mechanisms of Relativistic Electron Flux Dropout and Low Flux Maintenance During a Long Duration Sheath Region: a Case Study"
|-
|2||1:50 || Man Hua "The Dominant role of the electron isotropy boundary in controlling Earth's outer radiation belt electron lifetimes"
|-
|3||2:05 || Misty Chien "Storm-Time Preconditioning and Adiabatic Transport of MeV Electrons Observed by CIRBE/REPTile-2"
|-
|4||2:20 || Kelly Cantwell "Time Evolution of Microburst Events with BARREL: X-ray Pulsations"
|-
|5||2:35 || Wesley Martin "Multi-Satellite Observations of SEP Proton Contributions to the Trapped Radiation Belt"
|}
Remaining time for discussion.

=== 7/14/2026 (Tue) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': General contributions [5-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:37 || Xinlin Li "Radiation Belt Dynamics from a Low Earth Orbit Perspective: New Insights from CIRBE/REPTile-2"
|-
|2||1:44 || Yang Mei "Atmospheric effects controlling Earth's inner radiation belt electrons unveiled by LEO satellite measurements and simulations"
|-
|3||1:51 || Frances Staples "Statistical Characterization of Radiation Belt Electron Acceleration Timescales Using Van Allen Probes and GPS Observations"
|-
|4||1:58 || Lauren Blum "ultra-relativistic electrons in the slot region following geomagnetic storms"
|-
|5||2:05 || David Malaspina "Inferring growth and propagation of whistler-mode waves in the radiation belts using power spectral density distributions"
|-
|6||2:12 || Huayue Chen "Chorus Element Repetition: Roles of Energetic Electron Injection and Nonlinear Wave Growth"
|-
|7||2:19 || Huayue Chen "Generation of Falling-Tone Whistler-Mode Chorus Waves in the Earth’s Magnetosphere"
|-
|8||2:26 || Greg Riggs "Understanding the Role of ULF Wave Latitude Distribution in Radiation Belt Electron Radial Diffusion"
|-
|9||2:33 || Jinbei Huang "Modeling Magnetopause Shadowing of Outer Radiation Belt Electrons: From Drift-Averaged Radial Diffusion to MLT-Resolved Drift Diffusion"
|-
|10||2:40 || Zhiyang Xia "Investigate the Effect of Plasma Density Perturbation on the Hiss Wave Amplitude"
|-
|11||2:47 || Qiushuo Wang "Observations of the Latitude and Frequency Distributions of Equatorward-Propagating Chorus Waves"
|}
Remaining time for discussion.

=== 7/15/2024 (Wed) ===
*3:30 PM - 5 PM: '''RB SoS - MPEC joint session''': Radiation belt particle precipitation [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Myeong Joon Kim "Linear Instability Parameters Controlling Chorus Wave Modulation after the Onset of Pulsating Aurora"
|-
|2||1:55 || Qianli Ma "Modeling Radiation Belt Electron Fluxes Observed by ELFIN During the November 2021 Geomagnetic Storm"
|-
|3||2:15 || Alexander Drozdov "Intrinsic Hiss Waves and Their Role in Radiation Belt Dynamics"
|-
|4||2:35 || Zhi-Gu Li "Limits of the Bounce-Averaged Approximation: Pitch-Angle Diffusion and Electron Precipitation Near the Atmospheric Loss Cone"

|}
Remaining time for discussion.

=== 7/17/2026 (Fri) ===
*10:30 AM - 12 PM: '''RB SoS - topic session''': Cross-population coupling in the inner magnetosphere [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Ziye Zhang "The Role of the Plasmasphere in the Evolution of Reversed Radiation Belt Electron Energy Spectra."
|-
|2||1:55 || Taylor Whitney Aegerter "Electromagnetic Ion Cyclotron Waves in the Initial Phase of Geomagnetic Storms"
|-
|3||2:15 || Longzhi Gan "Bouncing Packets Driven by Ducted Lightning-Generated-Whistlers: Comparison with SAMPEX Observations"
|-
|4||2:35 || Shanshan Bao "Initial Results of Two-way Coupling of SAMI3 to the Whole Geospace Model, MAGE"
|}
Remaining time for discussion.

*1:30 PM - 3 PM: '''RB SoS - KiTs - MESO - MAC joint session''': Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere
**''Please refer to the KiTs Focus Group''

== Community resources ==

We are soliciting information on radiation belt products (models, datasets, events) that are useful to the community, in line with the deliverables outlined in our focus group proposal. We aim to collate this information and make it available to the community to facilitate collaboration across the radiation belts community. Examples of products that we aim to collect are datasets / models that can be used to study radiation belt dynamics and contact information of an expert who can be contacted for assistance with that data / model, specific events that you would like to highlight to the community, empirical models related to radiation belt dynamics, etc. If you would like to contribute to this database, please fill out this form: https://docs.google.com/forms/d/e/1FAIpQLSe5OpyJcP-A8Nd6_UNMEw4ZzzjGMov7wpRS0VTeCJEK54GMZA/viewform.

A list of products is available at: https://docs.google.com/spreadsheets/d/1lgc9SX86pXty5XQSFJA-YYt1l_lqT_KnAVfHepixmzY/edit?usp=sharing (navigate the tabs below to see different types).

== VERSIM x GEM Journal Club ==

The RB-SoS focus group is collaborating with VERSIM representatives to organise a journal club, which is held online on the first Wednesday of each month. Our goal is to create a friendly and lively environment where students can learn and engage, and build their scientific confidence. Information on the journal club (including the speaker schedule and zoom information) is available at https://aurora.troja.mff.cuni.cz/versim/index_jc.html.

== Mini-GEM 2025 ==

=== Schedule ===

The RB-SoS focus group will organise one session at the 2025 mini-GEM workshop. This will be held at 13:45 - 15:15 in room 383-385.

{| class="wikitable"
!#!! Time !! Presentations
|-
|1 ||13:45 || Louis Ozeke "A new database of large amplitude EMIC waves detected by the SWARM spacecraft"
|-
|2||13:55 || Xiaofei Shi "Statistical properties of quasi-periodic electron precipitation"
|-
|3||14:05 || Hong Zhao "Ultrarelativistic electron acceleration: Are satellite observations enough to identify the leading mechanism?"
|-
|4||14:15 || Hong Zhao "Bridging the radiation belt and ring current: new insights into energetic particle deep injection"
|-
|5||14:25 || Sergei Kamaletdinov "Energetic Electron Outward Radial Transport driven by Drift-Orbit Bifurcation"
|-
|6||14:35 || Alexander Drozdov "Python tools: Rbamlib and MTH5 Electric field data in PySPEDAS"
|-
|7||14:45 || Jay Albert "Resolution of the Greg Cunningham/quasilinear theory issue"
|-
|8||14:55 || Jay Albert "A model of Lauren Blum's periodic microburst observations"
|-
|9||15:05 || FG chairs: closing remarks
|-
|}

== Joint GEM / CEDAR Workshop 2025 ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== 6/24/2024 (Tue) ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== 6/25/2024 (Wed) ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|}

Remaining time for discussion.

=== 6/26/2024 (Thu) ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== 6/27/2024 (Fri) ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Harriet George,''' Institutet för rymdfysik (IRF) / Swedish Institute for Space Physics, harriet.george@irf.se
*'''Man Hua,''' School of Earth and Space Science and Technology, Wuhan University, huaman@whu.edu.cn
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Longzhi Gan''', Center for Space Physics, Boston University, lzgan@bu.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu (former chair).

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2026-07-08T07:20:53Z

RB-SoS: /* GEM workshop 2026 */

== GEM workshop 2026 ==

The RB-SoS is organising 5 sessions at the 2026 workshop; three stand-alone sessions and two joint sessions.
=== 7/13/2026 (Mon) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': Event specific dynamics and variability between events [12-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Karen Júlia Coldebella Ferreira "Competing Mechanisms of Relativistic Electron Flux Dropout and Low Flux Maintenance During a Long Duration Sheath Region: a Case Study"
|-
|2||1:50 || Man Hua "The Dominant role of the electron isotropy boundary in controlling Earth's outer radiation belt electron lifetimes"
|-
|3||2:05 || Misty Chien "Storm-Time Preconditioning and Adiabatic Transport of MeV Electrons Observed by CIRBE/REPTile-2"
|-
|4||2:20 || Kelly Cantwell "Time Evolution of Microburst Events with BARREL: X-ray Pulsations"
|-
|5||2:35 || Wesley Martin "Multi-Satellite Observations of SEP Proton Contributions to the Trapped Radiation Belt"
|}
Remaining time for discussion.

=== 7/14/2026 (Tue) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': General contributions [5-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:37 || Xinlin Li "Radiation Belt Dynamics from a Low Earth Orbit Perspective: New Insights from CIRBE/REPTile-2"
|-
|2||1:44 || Yang Mei "Atmospheric effects controlling Earth's inner radiation belt electrons unveiled by LEO satellite measurements and simulations"
|-
|3||1:51 || Frances Staples "Statistical Characterization of Radiation Belt Electron Acceleration Timescales Using Van Allen Probes and GPS Observations"
|-
|4||1:58 || Lauren Blum "ultra-relativistic electrons in the slot region following geomagnetic storms"
|-
|5||2:05 || David Malaspina "Inferring growth and propagation of whistler-mode waves in the radiation belts using power spectral density distributions"
|-
|6||2:12 || Huayue Chen "Chorus Element Repetition: Roles of Energetic Electron Injection and Nonlinear Wave Growth"
|-
|7||2:19 || Huayue Chen "Generation of Falling-Tone Whistler-Mode Chorus Waves in the Earth’s Magnetosphere"
|-
|8||2:26 || Greg Riggs "Understanding the Role of ULF Wave Latitude Distribution in Radiation Belt Electron Radial Diffusion"
|-
|9||2:33 || Jinbei Huang "Modeling Magnetopause Shadowing of Outer Radiation Belt Electrons: From Drift-Averaged Radial Diffusion to MLT-Resolved Drift Diffusion"
|-
|10||2:40 || Zhiyang Xia "Investigate the Effect of Plasma Density Perturbation on the Hiss Wave Amplitude"
|}
Remaining time for discussion.

=== 7/15/2024 (Wed) ===
*3:30 PM - 5 PM: '''RB SoS - MPEC joint session''': Radiation belt particle precipitation [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Myeong Joon Kim "Linear Instability Parameters Controlling Chorus Wave Modulation after the Onset of Pulsating Aurora"
|-
|2||1:55 || Qianli Ma "Modeling Radiation Belt Electron Fluxes Observed by ELFIN During the November 2021 Geomagnetic Storm"
|-
|3||2:15 || Alexander Drozdov "Intrinsic Hiss Waves and Their Role in Radiation Belt Dynamics"
|-
|4||2:35 || Zhi-Gu Li "Limits of the Bounce-Averaged Approximation: Pitch-Angle Diffusion and Electron Precipitation Near the Atmospheric Loss Cone"

|}
Remaining time for discussion.

=== 7/17/2026 (Fri) ===
*10:30 AM - 12 PM: '''RB SoS - topic session''': Cross-population coupling in the inner magnetosphere [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Ziye Zhang "The Role of the Plasmasphere in the Evolution of Reversed Radiation Belt Electron Energy Spectra."
|-
|2||1:55 || Taylor Whitney Aegerter "Electromagnetic Ion Cyclotron Waves in the Initial Phase of Geomagnetic Storms"
|-
|3||2:15 || Longzhi Gan "Bouncing Packets Driven by Ducted Lightning-Generated-Whistlers: Comparison with SAMPEX Observations"
|-
|4||2:35 || Shanshan Bao "Initial Results of Two-way Coupling of SAMI3 to the Whole Geospace Model, MAGE"
|}
Remaining time for discussion.

*1:30 PM - 3 PM: '''RB SoS - KiTs - MESO - MAC joint session''': Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere
**''Please refer to the KiTs Focus Group''

== Community resources ==

We are soliciting information on radiation belt products (models, datasets, events) that are useful to the community, in line with the deliverables outlined in our focus group proposal. We aim to collate this information and make it available to the community to facilitate collaboration across the radiation belts community. Examples of products that we aim to collect are datasets / models that can be used to study radiation belt dynamics and contact information of an expert who can be contacted for assistance with that data / model, specific events that you would like to highlight to the community, empirical models related to radiation belt dynamics, etc. If you would like to contribute to this database, please fill out this form: https://docs.google.com/forms/d/e/1FAIpQLSe5OpyJcP-A8Nd6_UNMEw4ZzzjGMov7wpRS0VTeCJEK54GMZA/viewform.

A list of products is available at: https://docs.google.com/spreadsheets/d/1lgc9SX86pXty5XQSFJA-YYt1l_lqT_KnAVfHepixmzY/edit?usp=sharing (navigate the tabs below to see different types).

== VERSIM x GEM Journal Club ==

The RB-SoS focus group is collaborating with VERSIM representatives to organise a journal club, which is held online on the first Wednesday of each month. Our goal is to create a friendly and lively environment where students can learn and engage, and build their scientific confidence. Information on the journal club (including the speaker schedule and zoom information) is available at https://aurora.troja.mff.cuni.cz/versim/index_jc.html.

== Mini-GEM 2025 ==

=== Schedule ===

The RB-SoS focus group will organise one session at the 2025 mini-GEM workshop. This will be held at 13:45 - 15:15 in room 383-385.

{| class="wikitable"
!#!! Time !! Presentations
|-
|1 ||13:45 || Louis Ozeke "A new database of large amplitude EMIC waves detected by the SWARM spacecraft"
|-
|2||13:55 || Xiaofei Shi "Statistical properties of quasi-periodic electron precipitation"
|-
|3||14:05 || Hong Zhao "Ultrarelativistic electron acceleration: Are satellite observations enough to identify the leading mechanism?"
|-
|4||14:15 || Hong Zhao "Bridging the radiation belt and ring current: new insights into energetic particle deep injection"
|-
|5||14:25 || Sergei Kamaletdinov "Energetic Electron Outward Radial Transport driven by Drift-Orbit Bifurcation"
|-
|6||14:35 || Alexander Drozdov "Python tools: Rbamlib and MTH5 Electric field data in PySPEDAS"
|-
|7||14:45 || Jay Albert "Resolution of the Greg Cunningham/quasilinear theory issue"
|-
|8||14:55 || Jay Albert "A model of Lauren Blum's periodic microburst observations"
|-
|9||15:05 || FG chairs: closing remarks
|-
|}

== Joint GEM / CEDAR Workshop 2025 ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== 6/24/2024 (Tue) ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== 6/25/2024 (Wed) ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|}

Remaining time for discussion.

=== 6/26/2024 (Thu) ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== 6/27/2024 (Fri) ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Harriet George,''' Institutet för rymdfysik (IRF) / Swedish Institute for Space Physics, harriet.george@irf.se
*'''Man Hua,''' School of Earth and Space Science and Technology, Wuhan University, huaman@whu.edu.cn
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Longzhi Gan''', Center for Space Physics, Boston University, lzgan@bu.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu (former chair).

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

GEM Focus Groups

2026-07-08T01:36:16Z

RB-SoS: /* Active Focus Groups */

__TOC__

==Introduction==
The hallmark of GEM workshops is its community-led workshop-style sessions, carried out through focus groups. Interested in applying to run a focus group and are not sure how to do it? Are you currently running a focus group and need ideas for how to achieve the workshop-style in your focus groups? Advice from previous focus group leaders on proposing and running a focus group, updated in October 2019, is available [http://gem.epss.ucla.edu/mediawiki/pdf/GEM_ForFocusGroupLeaders.pdf here].

==Active Focus Groups==

* [[FG: Understanding the causes of geomagnetic disturbances in geospace for hazard analysis on geomagnetically induced currents|(GIC) Understanding the causes of geomagnetic disturbances in geospace for hazard analysis on geomagnetically induced currents]] (2022 - 2026; Xueling Shi, Dogacan Su Ozturk, Mark Engebretson, Zhonghua Xu, E. Joshua Rigler; RA: Primary – GSM, Secondary – MIC)
*[[FG: Mesoscale drivers of the nightside transition region ionospheric and magnetotail evaluations|(MESO) Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations]] (2022 - 2026; Bea Gallardo-Lacourt, Gareth Perry, Emma Spanswick, and Vincent Ledvina; RA: Primary – MPS, Secondary – MIC).
* [[FG: Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems|(MPEC) Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems]] (2022 - 2026; Dogacan Su Ozturk, Dong Lin, Yiqun Yu, Katherine Garcia-Sage, Stephen Kaeppler; RA: Primary – MIC, Secondary – GSM)
* [[FG: Comparative Planetary Magnetospheric Processes|(COMP) Comparative Planetary Magnetospheric Processes]] (2023 - 2027; George Clark, Wen Li, Bob Marshall, Dan Gershman, Peter Delamere, Shannon Curry; RA: Primary – SWMI, Secondary – MPS)
* [[FG: Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics|(KiTS) Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics]] (2024 - 2028; Harry Arnold, Jason Derr, Akhtar Ardakani, Anton Artemyev; RA: Primary – MPS, Secondary – GSM)
* [[FG: Multiscale Dayside Transients and their Effect on Earth's Magnetosphere|(MDT) Multiscale Dayside Transients and their Effect on Earth's Magnetosphere]] (2025 - 2029; Savvas Raptis, Ivan Vasko, Yuxi Chen, Gonzalo Cucho-Padin, Imogen Gingell, Terry Z. Liu, Ying Zou, Runyi Liu, David Tonoian; RA: Primary - SWMI)
* [[FG: Magnetic Reconnection: The Key to Understanding Earth's Space Environment|(RX) Magnetic Reconnection: The Key to Understanding Earth's Space Environment]] (2025 - 2029; Yi Qi, John Dorelli, Katherine Goodrich, Chen Shi, M. Hasan Barbhuiya, Krishna Khanal; RA: Primary - SWMI, Secondary - GSM)
* [[FG: Radiation Belts as a System of Systems|(RBSoS) Radiation Belts as a System of Systems]] (RB-SoS) (2025 - 2029; Harriet George, Man Hua, Adam Michael, Luisa Capannolo, Longzhi Gan; RA: Primary - IMAG)
* [[FG: Magnetosphere-Aurora Connection|(MAC) Magnetosphere-Aurora Connection]] (MAC) (2026 - 2030; Toshi Nishimura, Tetsuo Motoba, Shannon Hill, and Bea Gallardo-Lacourt; RA: Primary – MIC, Secondary – MPS and IMAG)

(RA: Research Area).

==Standing Resource Groups==
* [[RG: Modeling Methods and Validation|Modeling Methods and Validation]] (2020 - present; Alexa Halford, Josh Rigler, Qusai Al Shidi, Huayue Chen)
* [[RG: Machine Learning|Machine Learning]] (2024 - present; Hyunju Connor, Bashi Ferdousi, Xiangning Chu, Matthew Argall, Valluri Sai Gowtam)

==Past Focus Groups==
* [[FG: The Impact of the Cold Plasma in Magnetospheric Physics|(CP) The Impact of the Cold Plasma in Magnetospheric Physics]] (2020 - 2025; Gian Luca Delzanno, Natalia Buzulukosva, Barbara Giles, Roger Varney, and Joe Borovsky; RA: Primary – IMAG, Secondary – None)
* [[FG: Self-Consistent Inner Magnetospheric Modeling|(SCIMM) Self-Consistent Inner Magnetospheric Modeling]] (2020 - 2025; Cristian Ferradas, Chao Yue, Jacob Bortnik, and Qianli Ma; RA: Primary – IMAG, Secondary – MIC)
* [[FG: Magnetic Reconnection in the Age of the Heliophysics System Observatory|Magnetic Reconnection in the Age of the Heliophysics System Observatory]] (2018 - 2024; Tori Wilder, Shan Wang, Michael Shay, and Anton Artemyev; RA: Primary – GSM, Secondary – None)
* [[FG: System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling|System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling]] (2019 - 2024; Hong Zhao, Lauren Blum, Sasha Ukhorskiy, and Xiangrong Fu; RA: Primary – IMAG, Secondary – None)
* [[FG: Particle Heating and Thermalization in Collisionless Shocks in the MMS Era|Particle Heating and Thermalization in Collisionless Shocks in the MMS Era]] (2019 - 2024; Lynn Wilson III, Li-Jen Chen, Katherine Goodrich, and Ivan Vasko; RA: Primary – SWMI, Secondary – None)
* [[FG: Magnetotail Dipolarization and Its Effects on the Inner Magnetosphere|Magnetotail Dipolarization and Its Effects on the Inner Magnetosphere]] (2017 - 2023; Christine Gabrielse, Matina Gkioulidou, Slava Merkin, Drew Turner, David Malaspina, and Adam Michael; RA: Primary – MPS, Secondary – IMAG)
* [[FG: Interhemispheric Approaches to Understand M-I Coupling (IHMIC)|Interhemispheric Approaches to Understand M-I Coupling (IHMIC)]] (2018 - 2023; Hyomin Kim, Robert Lysak, and Tomoko Matsuo; RA: Primary – MIC, Secondary – IMAG)
* [[FG: 3D Ionospheric Electrodynamics and Its Impact on the Magnetosphere-Ionosphere-Thermosphere Coupled System|3D Ionospheric Electrodynamics and Its Impact on the Magnetosphere-Ionosphere-Thermosphere Coupled System (IEMIT)]] (2017 - 2022; Hyunju Connor, Dogacan Ozturk, Gang Lu, and Bin Zhang; RA: Primary – MIC, Secondary – GSM)
* [[FG: Merged Modeling & Measurement of Injection Ionospheric Plasma into the Magnetosphere and Its Effects (M3-I2)|Merged Modeling & Measurement of Injection Ionospheric Plasma into the Magnetosphere (M3I2) and Its Effects -- Plasma Sheet, Ring Current, Substorm Dynamics]] (2016 - 2021; Shasha Zou, Barbara Giles, and Rick Chappell; RA: Primary – MIC, Secondary – None)
* [[FG: Dayside Kinetic Processes in Global Solar Wind-Magnetosphere Interaction|Dayside Kinetic Processes in Global Solar Wind-Magnetosphere Interaction]] (2016 - 2021; Heli Hietala, Xochitl Blanco-Cano, Gabor Toth, Andrew Dimmock, and Ying Zou; RA: Primary – SWMI, Secondary – GSM)
* [[FG: ULF Wave Modeling, Effects, and Applications|ULF wave Modeling, Effects, and Applications]] (2016 - 2021; Michael Hartinger, Kazue Takahashi, Alexander Drozdov, Maria Usanova, Brian Kress, and Xueling Shi; RA: Primary – GSM, Secondary – None)
* [[FG: Modeling Methods and Validation|Modeling Methods and Validation]] (2016 - 2019; Katherine Garcia-Sage, Rob Redmon, Mike Liemohn, Lutz Rastaetter; RA: GSM)
* [[FG: Testing Proposed Links between Mesoscale Auroral and Polar Cap Dynamics and Substorms|Testing Proposed Links between Mesoscale Auroral and Polar Cap Dynamics and Substorms]] (2015 - 2019; Toshi Nishimura, Kyle Murphy, Emma Spanswick, and Jian Yang; RA: MPS)
* [[FG: Tail Environment and Dynamics at Lunar Distances|Tail Environment and Dynamics at Lunar Distances]] (2015 - 2019; Chih-Ping Wang, Andrei Runov, David Sibeck, Viacheslav Merkin, and Yu Lin; RA: MPS, GSM, SWMI)
* [[FG: Geospace Systems Science|Geospace Systems Science]] (2014 - 2018; Joe Borovsky, Bill Lotko, Vadim Uritsky, and Juan Valdivia; Coordinators with CEDAR: Aaron Ridley and Josh Semeter; RA: GSM)
* [[FG: Inner Magnetosphere Cross-Energy/Population Interactions|Inner Magnetosphere Cross-Energy/Population Interactions]] (2014 - 2018; Yiqun Yu, Colby Lemon, Michael Liemohn, and Jichun Zhang; RA: IMAG)
* [[FG: Quantitative Assessment of Radiation Belt Modeling|Quantitative Assessment of Radiation Belt Modeling]] (2014 - 2018; Jay Albert, Wen Li, Steve Morley, and Weichao Tu; RA: IMAG)
* [[FG: Magnetic Reconnection in the Magnetosphere|Magnetic Reconnection in the Magnetosphere]] (2013 - 2017; Paul Cassak, Andrei Runov, Yi-Hsin Liu, and Brian Walsh; RA: GSM)
* [[FG: Storm-Time Inner Magnetosphere-Ionosphere Convection|Storm-Time Inner Magnetosphere-Ionosphere Convection]] (2013 - 2017; Joseph Baker, Michael Ruohoniemi, Stanislav Sazykin, Peter Chi, and Mark Engebretson; RA: IMAG, MIC)
* [[FG: Tail-Inner Magnetosphere Interactions|Tail-Inner Magnetosphere Interactions]] (2012 - 2016; Vassilis Angelopoulos, Pontus Brandt, John Lyon, and Frank Toffoletto; RA: MPS)
* [[FG: Transient Phenomena at the Magnetopause and Bow Shock and Their Ground Signatures|Transient Phenomena at the Magnetopause and Bow Shock and Their Ground Signatures]] (2012 - 2016; Hui Zhang, Q.-G. Zong, Michael Ruohoniemi, and David Murr; RA: SWMI)
* [[FG: Metrics and Validation|Metrics and Validation]] (2011 - 2015; T. Guild, L. Rastaetter, H. Singer; RA:GSM)
* [[FG: The Ionospheric Source of Magnetospheric Plasma|The Ionospheric Source of Magnetospheric Plasma--Measuring, Modeling and Merging into the GEM GGCM]] (2011 - 2015; R. Schunk, R. Chappell, D. Welling; RA: MIC, GSM)
* [[FG: Scientific Magnetic Mapping & Techniques|Scientific Magnetic Mapping & Techniques]] (2011 - 2015; E. Donovan, E. MacDonald, R. Millan; RA: MIC)
* [[FG: Radiation Belts and Wave Modeling|Radiation Belts and Wave Modeling]] (2010 - 2014; Y. Shprits, S. Elkington, J. Bortnik, C. Kletzing; RA:IMAG)
* [[FG: The Magnetosheath|The Magnetosheath]] (2010 - 2014; S. Petrinec, K. Nykyri; RA:SWMI)
* [[FG11. Plasmasphere-Magnetosphere Interactions|Plasmasphere-Magnetosphere Interactions]] (2008 - 2013; J. Goldstein and J. Borovsky; RA:IMS)
* [[FG12. Substorm Expansion Onset: The First 10 Minutes|Substorm Expansion Onset: The First 10 Minutes]] (2008 - 2013; V. Angelopoulos, S. Ohtani, K. Shiokawa; RA:Tail)
* [[FG13. Modes of Solar WInd-Magnetosphere Energy Transfer|Modes of Solar WInd-Magnetosphere Energy Transfer]] (2008 - 2013; B. McPherron, L. Kepko; RA:Tail)
* [[FG: Dayside FACs and Energy Deposition|Dayside FACs and Energy Deposition]] (2010 - 2012; D. Knipp, G. Crowley, S. Eriksson, R. Lopez; RA:Dayside, MIC)
* [[FG8. Near Earth Magnetosphere: plasma, fields, and coupling|Near Earth Magnetosphere: plasma, fields, and coupling]] (2007 - 2012; S. Zaharia, S. Sazykin, B. Lavraud; RA: IMS, Tail)
* [[FG10. Diffuse Auroral Precipitation|Diffuse Auroral Precipitation]] (2006 - 2011, RA: MIC, IMS)
* [http://virbo.org/GEMFG9 Space Radiation Climatology] (2006 - 2011, RA: IMS, see also [http://groups.google.com/group/gem-2007-space-radiation-climatology-fg9 FG9 google email group])
* [[FG4. Plasma Entry and Transport into and within the Magnetotail|Plasma Entry and Transport into and within the Magnetotail]] (2006 - 2011, RA: Tail)
* [[FG6. Cusp Physics|Cusp Physics]] (2006-2010, RA: Dayside)
* [[FG1. GGCM Metrics and Validation|GGCM Metrics and Validation]] (2005 - 2010, RA: GGCM)
* [[FG2. GGCM Modules and Methods|GGCM Modules and Methods]] (2005 - 2010, RA: GGCM)
* [[FG3. Foreshock, Bowshock, Magnetosheath|Foreshock, Bowshock, Magnetosheath]] (2004 - 2009, RA: Dayside)
* [[FG5. Dayside Magnetopause Reconnection|Dayside Magnetopause Reconnection]] (2004 - 2009, RA: Dayside)
* [[FG7. MIC Electrodynamics|MIC Electrodynamics]] (2003 - 2008, RA: MIC)

(RA: Research Area)

FG: Radiation Belts as a System of Systems

2026-07-08T01:35:03Z

RB-SoS: /* Chairs */

== GEM workshop 2026 ==

=== Soliciting contributions ===

The RB-SoS focus group is currently soliciting presentations for the 2026 GEM workshop. The RB-SoS focus group is organising five sessions: three stand alone sessions, one joint session with the MPEC focus group, and one joint session with the KiTs, MESO and MAC focus groups.

The topics of these sessions are:
# Stand alone session 1: General contributions related to radiation belt dynamics.
# Stand alone session 2: Cross-population coupling in the inner magnetosphere, e.g. the coupling between the radiation belts and plasmasphere or ring current.
# Stand alone session 3: Event specific dynamics and variability between events, such as evaluating the role of adiabatic vs. non-adiabatic dynamics, radiation belt preconditioning or substorm level during case studies.
# RB-SoS / MPEC joint session: Radiation belt particle precipitation and its drivers, and the ionospheric impacts of this precipitation
# RB-SoS / KiTs / MESO / MAC joint session: Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere, with emphasis on near-Earth reconnection, particle injections, radiation-belt transport, and MI coupling.

To request a presentation in one of these sessions, please fill out this form https://forms.gle/7dBHBybMbr5VwxjV7 by July 6.

The RB-SoS is organising 5 sessions at the 2026 workshop; three stand-alone sessions and two joint sessions.
=== 7/13/2026 (Mon) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': Event specific dynamics and variability between events [12-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Karen Júlia Coldebella Ferreira "Competing Mechanisms of Relativistic Electron Flux Dropout and Low Flux Maintenance During a Long Duration Sheath Region: a Case Study"
|-
|2||1:50 || Man Hua "The Dominant role of the electron isotropy boundary in controlling Earth's outer radiation belt electron lifetimes"
|-
|3||2:05 || Misty Chien "Storm-Time Preconditioning and Adiabatic Transport of MeV Electrons Observed by CIRBE/REPTile-2"
|-
|4||2:20 || Kelly Cantwell "Time Evolution of Microburst Events with BARREL: X-ray Pulsations"
|-
|5||2:35 || Wesley Martin "Multi-Satellite Observations of SEP Proton Contributions to the Trapped Radiation Belt"
|}
Remaining time for discussion.

=== 7/14/2026 (Tue) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': General contributions [5-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:37 || Xinlin Li "Radiation Belt Dynamics from a Low Earth Orbit Perspective: New Insights from CIRBE/REPTile-2"
|-
|2||1:44 || Yang Mei "Atmospheric effects controlling Earth's inner radiation belt electrons unveiled by LEO satellite measurements and simulations"
|-
|3||1:51 || Frances Staples "Statistical Characterization of Radiation Belt Electron Acceleration Timescales Using Van Allen Probes and GPS Observations"
|-
|4||1:58 || Lauren Blum "ultra-relativistic electrons in the slot region following geomagnetic storms"
|-
|5||2:05 || David Malaspina "Inferring growth and propagation of whistler-mode waves in the radiation belts using power spectral density distributions"
|-
|6||2:12 || Huayue Chen "Chorus Element Repetition: Roles of Energetic Electron Injection and Nonlinear Wave Growth"
|-
|7||2:19 || Huayue Chen "Generation of Falling-Tone Whistler-Mode Chorus Waves in the Earth’s Magnetosphere"
|-
|8||2:26 || Greg Riggs "Understanding the Role of ULF Wave Latitude Distribution in Radiation Belt Electron Radial Diffusion"
|-
|9||2:33 || Jinbei Huang "Modeling Magnetopause Shadowing of Outer Radiation Belt Electrons: From Drift-Averaged Radial Diffusion to MLT-Resolved Drift Diffusion"
|-
|10||2:40 || Zhiyang Xia "Investigate the Effect of Plasma Density Perturbation on the Hiss Wave Amplitude"
|}
Remaining time for discussion.

=== 7/15/2024 (Wed) ===
*3:30 PM - 5 PM: '''RB SoS - MPEC joint session''': Radiation belt particle precipitation [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Myeong Joon Kim "Linear Instability Parameters Controlling Chorus Wave Modulation after the Onset of Pulsating Aurora"
|-
|2||1:55 || Qianli Ma "Modeling Radiation Belt Electron Fluxes Observed by ELFIN During the November 2021 Geomagnetic Storm"
|-
|3||2:15 || Alexander Drozdov "Intrinsic Hiss Waves and Their Role in Radiation Belt Dynamics"
|-
|4||2:35 || Zhi-Gu Li "Limits of the Bounce-Averaged Approximation: Pitch-Angle Diffusion and Electron Precipitation Near the Atmospheric Loss Cone"

|}
Remaining time for discussion.

=== 7/17/2026 (Fri) ===
*10:30 AM - 12 PM: '''RB SoS - topic session''': Cross-population coupling in the inner magnetosphere [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Ziye Zhang "The Role of the Plasmasphere in the Evolution of Reversed Radiation Belt Electron Energy Spectra."
|-
|2||1:55 || Taylor Whitney Aegerter "Electromagnetic Ion Cyclotron Waves in the Initial Phase of Geomagnetic Storms"
|-
|3||2:15 || Longzhi Gan "Bouncing Packets Driven by Ducted Lightning-Generated-Whistlers: Comparison with SAMPEX Observations"
|-
|4||2:35 || Shanshan Bao "Initial Results of Two-way Coupling of SAMI3 to the Whole Geospace Model, MAGE"
|}
Remaining time for discussion.

*1:30 PM - 3 PM: '''RB SoS - KiTs - MESO - MAC joint session''': Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere
**''Please refer to the KiTs Focus Group''

== Community resources ==

We are soliciting information on radiation belt products (models, datasets, events) that are useful to the community, in line with the deliverables outlined in our focus group proposal. We aim to collate this information and make it available to the community to facilitate collaboration across the radiation belts community. Examples of products that we aim to collect are datasets / models that can be used to study radiation belt dynamics and contact information of an expert who can be contacted for assistance with that data / model, specific events that you would like to highlight to the community, empirical models related to radiation belt dynamics, etc. If you would like to contribute to this database, please fill out this form: https://docs.google.com/forms/d/e/1FAIpQLSe5OpyJcP-A8Nd6_UNMEw4ZzzjGMov7wpRS0VTeCJEK54GMZA/viewform.

A list of products is available at: https://docs.google.com/spreadsheets/d/1lgc9SX86pXty5XQSFJA-YYt1l_lqT_KnAVfHepixmzY/edit?usp=sharing (navigate the tabs below to see different types).

== VERSIM x GEM Journal Club ==

The RB-SoS focus group is collaborating with VERSIM representatives to organise a journal club, which is held online on the first Wednesday of each month. Our goal is to create a friendly and lively environment where students can learn and engage, and build their scientific confidence. Information on the journal club (including the speaker schedule and zoom information) is available at https://aurora.troja.mff.cuni.cz/versim/index_jc.html.

== Mini-GEM 2025 ==

=== Schedule ===

The RB-SoS focus group will organise one session at the 2025 mini-GEM workshop. This will be held at 13:45 - 15:15 in room 383-385.

{| class="wikitable"
!#!! Time !! Presentations
|-
|1 ||13:45 || Louis Ozeke "A new database of large amplitude EMIC waves detected by the SWARM spacecraft"
|-
|2||13:55 || Xiaofei Shi "Statistical properties of quasi-periodic electron precipitation"
|-
|3||14:05 || Hong Zhao "Ultrarelativistic electron acceleration: Are satellite observations enough to identify the leading mechanism?"
|-
|4||14:15 || Hong Zhao "Bridging the radiation belt and ring current: new insights into energetic particle deep injection"
|-
|5||14:25 || Sergei Kamaletdinov "Energetic Electron Outward Radial Transport driven by Drift-Orbit Bifurcation"
|-
|6||14:35 || Alexander Drozdov "Python tools: Rbamlib and MTH5 Electric field data in PySPEDAS"
|-
|7||14:45 || Jay Albert "Resolution of the Greg Cunningham/quasilinear theory issue"
|-
|8||14:55 || Jay Albert "A model of Lauren Blum's periodic microburst observations"
|-
|9||15:05 || FG chairs: closing remarks
|-
|}

== Joint GEM / CEDAR Workshop 2025 ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== 6/24/2024 (Tue) ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== 6/25/2024 (Wed) ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|}

Remaining time for discussion.

=== 6/26/2024 (Thu) ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== 6/27/2024 (Fri) ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Harriet George,''' Institutet för rymdfysik (IRF) / Swedish Institute for Space Physics, harriet.george@irf.se
*'''Man Hua,''' School of Earth and Space Science and Technology, Wuhan University, huaman@whu.edu.cn
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Longzhi Gan''', Center for Space Physics, Boston University, lzgan@bu.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu (former chair).

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2026-07-08T01:34:47Z

RB-SoS: /* Chairs */

== GEM workshop 2026 ==

=== Soliciting contributions ===

The RB-SoS focus group is currently soliciting presentations for the 2026 GEM workshop. The RB-SoS focus group is organising five sessions: three stand alone sessions, one joint session with the MPEC focus group, and one joint session with the KiTs, MESO and MAC focus groups.

The topics of these sessions are:
# Stand alone session 1: General contributions related to radiation belt dynamics.
# Stand alone session 2: Cross-population coupling in the inner magnetosphere, e.g. the coupling between the radiation belts and plasmasphere or ring current.
# Stand alone session 3: Event specific dynamics and variability between events, such as evaluating the role of adiabatic vs. non-adiabatic dynamics, radiation belt preconditioning or substorm level during case studies.
# RB-SoS / MPEC joint session: Radiation belt particle precipitation and its drivers, and the ionospheric impacts of this precipitation
# RB-SoS / KiTs / MESO / MAC joint session: Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere, with emphasis on near-Earth reconnection, particle injections, radiation-belt transport, and MI coupling.

To request a presentation in one of these sessions, please fill out this form https://forms.gle/7dBHBybMbr5VwxjV7 by July 6.

The RB-SoS is organising 5 sessions at the 2026 workshop; three stand-alone sessions and two joint sessions.
=== 7/13/2026 (Mon) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': Event specific dynamics and variability between events [12-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Karen Júlia Coldebella Ferreira "Competing Mechanisms of Relativistic Electron Flux Dropout and Low Flux Maintenance During a Long Duration Sheath Region: a Case Study"
|-
|2||1:50 || Man Hua "The Dominant role of the electron isotropy boundary in controlling Earth's outer radiation belt electron lifetimes"
|-
|3||2:05 || Misty Chien "Storm-Time Preconditioning and Adiabatic Transport of MeV Electrons Observed by CIRBE/REPTile-2"
|-
|4||2:20 || Kelly Cantwell "Time Evolution of Microburst Events with BARREL: X-ray Pulsations"
|-
|5||2:35 || Wesley Martin "Multi-Satellite Observations of SEP Proton Contributions to the Trapped Radiation Belt"
|}
Remaining time for discussion.

=== 7/14/2026 (Tue) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': General contributions [5-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:37 || Xinlin Li "Radiation Belt Dynamics from a Low Earth Orbit Perspective: New Insights from CIRBE/REPTile-2"
|-
|2||1:44 || Yang Mei "Atmospheric effects controlling Earth's inner radiation belt electrons unveiled by LEO satellite measurements and simulations"
|-
|3||1:51 || Frances Staples "Statistical Characterization of Radiation Belt Electron Acceleration Timescales Using Van Allen Probes and GPS Observations"
|-
|4||1:58 || Lauren Blum "ultra-relativistic electrons in the slot region following geomagnetic storms"
|-
|5||2:05 || David Malaspina "Inferring growth and propagation of whistler-mode waves in the radiation belts using power spectral density distributions"
|-
|6||2:12 || Huayue Chen "Chorus Element Repetition: Roles of Energetic Electron Injection and Nonlinear Wave Growth"
|-
|7||2:19 || Huayue Chen "Generation of Falling-Tone Whistler-Mode Chorus Waves in the Earth’s Magnetosphere"
|-
|8||2:26 || Greg Riggs "Understanding the Role of ULF Wave Latitude Distribution in Radiation Belt Electron Radial Diffusion"
|-
|9||2:33 || Jinbei Huang "Modeling Magnetopause Shadowing of Outer Radiation Belt Electrons: From Drift-Averaged Radial Diffusion to MLT-Resolved Drift Diffusion"
|-
|10||2:40 || Zhiyang Xia "Investigate the Effect of Plasma Density Perturbation on the Hiss Wave Amplitude"
|}
Remaining time for discussion.

=== 7/15/2024 (Wed) ===
*3:30 PM - 5 PM: '''RB SoS - MPEC joint session''': Radiation belt particle precipitation [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Myeong Joon Kim "Linear Instability Parameters Controlling Chorus Wave Modulation after the Onset of Pulsating Aurora"
|-
|2||1:55 || Qianli Ma "Modeling Radiation Belt Electron Fluxes Observed by ELFIN During the November 2021 Geomagnetic Storm"
|-
|3||2:15 || Alexander Drozdov "Intrinsic Hiss Waves and Their Role in Radiation Belt Dynamics"
|-
|4||2:35 || Zhi-Gu Li "Limits of the Bounce-Averaged Approximation: Pitch-Angle Diffusion and Electron Precipitation Near the Atmospheric Loss Cone"

|}
Remaining time for discussion.

=== 7/17/2026 (Fri) ===
*10:30 AM - 12 PM: '''RB SoS - topic session''': Cross-population coupling in the inner magnetosphere [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Ziye Zhang "The Role of the Plasmasphere in the Evolution of Reversed Radiation Belt Electron Energy Spectra."
|-
|2||1:55 || Taylor Whitney Aegerter "Electromagnetic Ion Cyclotron Waves in the Initial Phase of Geomagnetic Storms"
|-
|3||2:15 || Longzhi Gan "Bouncing Packets Driven by Ducted Lightning-Generated-Whistlers: Comparison with SAMPEX Observations"
|-
|4||2:35 || Shanshan Bao "Initial Results of Two-way Coupling of SAMI3 to the Whole Geospace Model, MAGE"
|}
Remaining time for discussion.

*1:30 PM - 3 PM: '''RB SoS - KiTs - MESO - MAC joint session''': Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere
**''Please refer to the KiTs Focus Group''

== Community resources ==

We are soliciting information on radiation belt products (models, datasets, events) that are useful to the community, in line with the deliverables outlined in our focus group proposal. We aim to collate this information and make it available to the community to facilitate collaboration across the radiation belts community. Examples of products that we aim to collect are datasets / models that can be used to study radiation belt dynamics and contact information of an expert who can be contacted for assistance with that data / model, specific events that you would like to highlight to the community, empirical models related to radiation belt dynamics, etc. If you would like to contribute to this database, please fill out this form: https://docs.google.com/forms/d/e/1FAIpQLSe5OpyJcP-A8Nd6_UNMEw4ZzzjGMov7wpRS0VTeCJEK54GMZA/viewform.

A list of products is available at: https://docs.google.com/spreadsheets/d/1lgc9SX86pXty5XQSFJA-YYt1l_lqT_KnAVfHepixmzY/edit?usp=sharing (navigate the tabs below to see different types).

== VERSIM x GEM Journal Club ==

The RB-SoS focus group is collaborating with VERSIM representatives to organise a journal club, which is held online on the first Wednesday of each month. Our goal is to create a friendly and lively environment where students can learn and engage, and build their scientific confidence. Information on the journal club (including the speaker schedule and zoom information) is available at https://aurora.troja.mff.cuni.cz/versim/index_jc.html.

== Mini-GEM 2025 ==

=== Schedule ===

The RB-SoS focus group will organise one session at the 2025 mini-GEM workshop. This will be held at 13:45 - 15:15 in room 383-385.

{| class="wikitable"
!#!! Time !! Presentations
|-
|1 ||13:45 || Louis Ozeke "A new database of large amplitude EMIC waves detected by the SWARM spacecraft"
|-
|2||13:55 || Xiaofei Shi "Statistical properties of quasi-periodic electron precipitation"
|-
|3||14:05 || Hong Zhao "Ultrarelativistic electron acceleration: Are satellite observations enough to identify the leading mechanism?"
|-
|4||14:15 || Hong Zhao "Bridging the radiation belt and ring current: new insights into energetic particle deep injection"
|-
|5||14:25 || Sergei Kamaletdinov "Energetic Electron Outward Radial Transport driven by Drift-Orbit Bifurcation"
|-
|6||14:35 || Alexander Drozdov "Python tools: Rbamlib and MTH5 Electric field data in PySPEDAS"
|-
|7||14:45 || Jay Albert "Resolution of the Greg Cunningham/quasilinear theory issue"
|-
|8||14:55 || Jay Albert "A model of Lauren Blum's periodic microburst observations"
|-
|9||15:05 || FG chairs: closing remarks
|-
|}

== Joint GEM / CEDAR Workshop 2025 ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== 6/24/2024 (Tue) ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== 6/25/2024 (Wed) ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|}

Remaining time for discussion.

=== 6/26/2024 (Thu) ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== 6/27/2024 (Fri) ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Harriet George,''' Institutet för rymdfysik (IRF) / Swedish Institute for Space Physics, harriet.george@irf.se
*'''Man Hua,''' School of Earth and Space Science and Technology, Wuhan University, huaman@whu.edu.cn.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Longzhi Gan''', Center for Space Physics, Boston University, lzgan@bu.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu (former chair).

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2026-07-08T01:33:35Z

RB-SoS: /* Chairs */

== GEM workshop 2026 ==

=== Soliciting contributions ===

The RB-SoS focus group is currently soliciting presentations for the 2026 GEM workshop. The RB-SoS focus group is organising five sessions: three stand alone sessions, one joint session with the MPEC focus group, and one joint session with the KiTs, MESO and MAC focus groups.

The topics of these sessions are:
# Stand alone session 1: General contributions related to radiation belt dynamics.
# Stand alone session 2: Cross-population coupling in the inner magnetosphere, e.g. the coupling between the radiation belts and plasmasphere or ring current.
# Stand alone session 3: Event specific dynamics and variability between events, such as evaluating the role of adiabatic vs. non-adiabatic dynamics, radiation belt preconditioning or substorm level during case studies.
# RB-SoS / MPEC joint session: Radiation belt particle precipitation and its drivers, and the ionospheric impacts of this precipitation
# RB-SoS / KiTs / MESO / MAC joint session: Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere, with emphasis on near-Earth reconnection, particle injections, radiation-belt transport, and MI coupling.

To request a presentation in one of these sessions, please fill out this form https://forms.gle/7dBHBybMbr5VwxjV7 by July 6.

The RB-SoS is organising 5 sessions at the 2026 workshop; three stand-alone sessions and two joint sessions.
=== 7/13/2026 (Mon) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': Event specific dynamics and variability between events [12-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Karen Júlia Coldebella Ferreira "Competing Mechanisms of Relativistic Electron Flux Dropout and Low Flux Maintenance During a Long Duration Sheath Region: a Case Study"
|-
|2||1:50 || Man Hua "The Dominant role of the electron isotropy boundary in controlling Earth's outer radiation belt electron lifetimes"
|-
|3||2:05 || Misty Chien "Storm-Time Preconditioning and Adiabatic Transport of MeV Electrons Observed by CIRBE/REPTile-2"
|-
|4||2:20 || Kelly Cantwell "Time Evolution of Microburst Events with BARREL: X-ray Pulsations"
|-
|5||2:35 || Wesley Martin "Multi-Satellite Observations of SEP Proton Contributions to the Trapped Radiation Belt"
|}
Remaining time for discussion.

=== 7/14/2026 (Tue) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': General contributions [5-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:37 || Xinlin Li "Radiation Belt Dynamics from a Low Earth Orbit Perspective: New Insights from CIRBE/REPTile-2"
|-
|2||1:44 || Yang Mei "Atmospheric effects controlling Earth's inner radiation belt electrons unveiled by LEO satellite measurements and simulations"
|-
|3||1:51 || Frances Staples "Statistical Characterization of Radiation Belt Electron Acceleration Timescales Using Van Allen Probes and GPS Observations"
|-
|4||1:58 || Lauren Blum "ultra-relativistic electrons in the slot region following geomagnetic storms"
|-
|5||2:05 || David Malaspina "Inferring growth and propagation of whistler-mode waves in the radiation belts using power spectral density distributions"
|-
|6||2:12 || Huayue Chen "Chorus Element Repetition: Roles of Energetic Electron Injection and Nonlinear Wave Growth"
|-
|7||2:19 || Huayue Chen "Generation of Falling-Tone Whistler-Mode Chorus Waves in the Earth’s Magnetosphere"
|-
|8||2:26 || Greg Riggs "Understanding the Role of ULF Wave Latitude Distribution in Radiation Belt Electron Radial Diffusion"
|-
|9||2:33 || Jinbei Huang "Modeling Magnetopause Shadowing of Outer Radiation Belt Electrons: From Drift-Averaged Radial Diffusion to MLT-Resolved Drift Diffusion"
|-
|10||2:40 || Zhiyang Xia "Investigate the Effect of Plasma Density Perturbation on the Hiss Wave Amplitude"
|}
Remaining time for discussion.

=== 7/15/2024 (Wed) ===
*3:30 PM - 5 PM: '''RB SoS - MPEC joint session''': Radiation belt particle precipitation [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Myeong Joon Kim "Linear Instability Parameters Controlling Chorus Wave Modulation after the Onset of Pulsating Aurora"
|-
|2||1:55 || Qianli Ma "Modeling Radiation Belt Electron Fluxes Observed by ELFIN During the November 2021 Geomagnetic Storm"
|-
|3||2:15 || Alexander Drozdov "Intrinsic Hiss Waves and Their Role in Radiation Belt Dynamics"
|-
|4||2:35 || Zhi-Gu Li "Limits of the Bounce-Averaged Approximation: Pitch-Angle Diffusion and Electron Precipitation Near the Atmospheric Loss Cone"

|}
Remaining time for discussion.

=== 7/17/2026 (Fri) ===
*10:30 AM - 12 PM: '''RB SoS - topic session''': Cross-population coupling in the inner magnetosphere [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Ziye Zhang "The Role of the Plasmasphere in the Evolution of Reversed Radiation Belt Electron Energy Spectra."
|-
|2||1:55 || Taylor Whitney Aegerter "Electromagnetic Ion Cyclotron Waves in the Initial Phase of Geomagnetic Storms"
|-
|3||2:15 || Longzhi Gan "Bouncing Packets Driven by Ducted Lightning-Generated-Whistlers: Comparison with SAMPEX Observations"
|-
|4||2:35 || Shanshan Bao "Initial Results of Two-way Coupling of SAMI3 to the Whole Geospace Model, MAGE"
|}
Remaining time for discussion.

*1:30 PM - 3 PM: '''RB SoS - KiTs - MESO - MAC joint session''': Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere
**''Please refer to the KiTs Focus Group''

== Community resources ==

We are soliciting information on radiation belt products (models, datasets, events) that are useful to the community, in line with the deliverables outlined in our focus group proposal. We aim to collate this information and make it available to the community to facilitate collaboration across the radiation belts community. Examples of products that we aim to collect are datasets / models that can be used to study radiation belt dynamics and contact information of an expert who can be contacted for assistance with that data / model, specific events that you would like to highlight to the community, empirical models related to radiation belt dynamics, etc. If you would like to contribute to this database, please fill out this form: https://docs.google.com/forms/d/e/1FAIpQLSe5OpyJcP-A8Nd6_UNMEw4ZzzjGMov7wpRS0VTeCJEK54GMZA/viewform.

A list of products is available at: https://docs.google.com/spreadsheets/d/1lgc9SX86pXty5XQSFJA-YYt1l_lqT_KnAVfHepixmzY/edit?usp=sharing (navigate the tabs below to see different types).

== VERSIM x GEM Journal Club ==

The RB-SoS focus group is collaborating with VERSIM representatives to organise a journal club, which is held online on the first Wednesday of each month. Our goal is to create a friendly and lively environment where students can learn and engage, and build their scientific confidence. Information on the journal club (including the speaker schedule and zoom information) is available at https://aurora.troja.mff.cuni.cz/versim/index_jc.html.

== Mini-GEM 2025 ==

=== Schedule ===

The RB-SoS focus group will organise one session at the 2025 mini-GEM workshop. This will be held at 13:45 - 15:15 in room 383-385.

{| class="wikitable"
!#!! Time !! Presentations
|-
|1 ||13:45 || Louis Ozeke "A new database of large amplitude EMIC waves detected by the SWARM spacecraft"
|-
|2||13:55 || Xiaofei Shi "Statistical properties of quasi-periodic electron precipitation"
|-
|3||14:05 || Hong Zhao "Ultrarelativistic electron acceleration: Are satellite observations enough to identify the leading mechanism?"
|-
|4||14:15 || Hong Zhao "Bridging the radiation belt and ring current: new insights into energetic particle deep injection"
|-
|5||14:25 || Sergei Kamaletdinov "Energetic Electron Outward Radial Transport driven by Drift-Orbit Bifurcation"
|-
|6||14:35 || Alexander Drozdov "Python tools: Rbamlib and MTH5 Electric field data in PySPEDAS"
|-
|7||14:45 || Jay Albert "Resolution of the Greg Cunningham/quasilinear theory issue"
|-
|8||14:55 || Jay Albert "A model of Lauren Blum's periodic microburst observations"
|-
|9||15:05 || FG chairs: closing remarks
|-
|}

== Joint GEM / CEDAR Workshop 2025 ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== 6/24/2024 (Tue) ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== 6/25/2024 (Wed) ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|}

Remaining time for discussion.

=== 6/26/2024 (Thu) ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== 6/27/2024 (Fri) ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Harriet George,''' Institutet för rymdfysik (IRF) / Swedish Institute for Space Physics, harriet.george@irf.se
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, huaman@whu.edu.cn.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Longzhi Gan''', Center for Space Physics, Boston University, lzgan@bu.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu (former chair).

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2026-07-07T18:16:05Z

RB-SoS: /* 7/17/2026 (Fri) */

== GEM workshop 2026 ==

=== Soliciting contributions ===

The RB-SoS focus group is currently soliciting presentations for the 2026 GEM workshop. The RB-SoS focus group is organising five sessions: three stand alone sessions, one joint session with the MPEC focus group, and one joint session with the KiTs, MESO and MAC focus groups.

The topics of these sessions are:
# Stand alone session 1: General contributions related to radiation belt dynamics.
# Stand alone session 2: Cross-population coupling in the inner magnetosphere, e.g. the coupling between the radiation belts and plasmasphere or ring current.
# Stand alone session 3: Event specific dynamics and variability between events, such as evaluating the role of adiabatic vs. non-adiabatic dynamics, radiation belt preconditioning or substorm level during case studies.
# RB-SoS / MPEC joint session: Radiation belt particle precipitation and its drivers, and the ionospheric impacts of this precipitation
# RB-SoS / KiTs / MESO / MAC joint session: Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere, with emphasis on near-Earth reconnection, particle injections, radiation-belt transport, and MI coupling.

To request a presentation in one of these sessions, please fill out this form https://forms.gle/7dBHBybMbr5VwxjV7 by July 6.

The RB-SoS is organising 5 sessions at the 2026 workshop; three stand-alone sessions and two joint sessions.
=== 7/13/2026 (Mon) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': Event specific dynamics and variability between events [12-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Karen Júlia Coldebella Ferreira "Competing Mechanisms of Relativistic Electron Flux Dropout and Low Flux Maintenance During a Long Duration Sheath Region: a Case Study"
|-
|2||1:50 || Man Hua "The Dominant role of the electron isotropy boundary in controlling Earth's outer radiation belt electron lifetimes"
|-
|3||2:05 || Misty Chien "Storm-Time Preconditioning and Adiabatic Transport of MeV Electrons Observed by CIRBE/REPTile-2"
|-
|4||2:20 || Kelly Cantwell "Time Evolution of Microburst Events with BARREL: X-ray Pulsations"
|-
|5||2:35 || Wesley Martin "Multi-Satellite Observations of SEP Proton Contributions to the Trapped Radiation Belt"
|}
Remaining time for discussion.

=== 7/14/2026 (Tue) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': General contributions [5-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:37 || Xinlin Li "Radiation Belt Dynamics from a Low Earth Orbit Perspective: New Insights from CIRBE/REPTile-2"
|-
|2||1:44 || Yang Mei "Atmospheric effects controlling Earth's inner radiation belt electrons unveiled by LEO satellite measurements and simulations"
|-
|3||1:51 || Frances Staples "Statistical Characterization of Radiation Belt Electron Acceleration Timescales Using Van Allen Probes and GPS Observations"
|-
|4||1:58 || Lauren Blum "ultra-relativistic electrons in the slot region following geomagnetic storms"
|-
|5||2:05 || David Malaspina "Inferring growth and propagation of whistler-mode waves in the radiation belts using power spectral density distributions"
|-
|6||2:12 || Huayue Chen "Chorus Element Repetition: Roles of Energetic Electron Injection and Nonlinear Wave Growth"
|-
|7||2:19 || Huayue Chen "Generation of Falling-Tone Whistler-Mode Chorus Waves in the Earth’s Magnetosphere"
|-
|8||2:26 || Greg Riggs "Understanding the Role of ULF Wave Latitude Distribution in Radiation Belt Electron Radial Diffusion"
|-
|9||2:33 || Jinbei Huang "Modeling Magnetopause Shadowing of Outer Radiation Belt Electrons: From Drift-Averaged Radial Diffusion to MLT-Resolved Drift Diffusion"
|-
|10||2:40 || Zhiyang Xia "Investigate the Effect of Plasma Density Perturbation on the Hiss Wave Amplitude"
|}
Remaining time for discussion.

=== 7/15/2024 (Wed) ===
*3:30 PM - 5 PM: '''RB SoS - MPEC joint session''': Radiation belt particle precipitation [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Myeong Joon Kim "Linear Instability Parameters Controlling Chorus Wave Modulation after the Onset of Pulsating Aurora"
|-
|2||1:55 || Qianli Ma "Modeling Radiation Belt Electron Fluxes Observed by ELFIN During the November 2021 Geomagnetic Storm"
|-
|3||2:15 || Alexander Drozdov "Intrinsic Hiss Waves and Their Role in Radiation Belt Dynamics"
|-
|4||2:35 || Zhi-Gu Li "Limits of the Bounce-Averaged Approximation: Pitch-Angle Diffusion and Electron Precipitation Near the Atmospheric Loss Cone"

|}
Remaining time for discussion.

=== 7/17/2026 (Fri) ===
*10:30 AM - 12 PM: '''RB SoS - topic session''': Cross-population coupling in the inner magnetosphere [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Ziye Zhang "The Role of the Plasmasphere in the Evolution of Reversed Radiation Belt Electron Energy Spectra."
|-
|2||1:55 || Taylor Whitney Aegerter "Electromagnetic Ion Cyclotron Waves in the Initial Phase of Geomagnetic Storms"
|-
|3||2:15 || Longzhi Gan "Bouncing Packets Driven by Ducted Lightning-Generated-Whistlers: Comparison with SAMPEX Observations"
|-
|4||2:35 || Shanshan Bao "Initial Results of Two-way Coupling of SAMI3 to the Whole Geospace Model, MAGE"
|}
Remaining time for discussion.

*1:30 PM - 3 PM: '''RB SoS - KiTs - MESO - MAC joint session''': Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere
**''Please refer to the KiTs Focus Group''

== Community resources ==

We are soliciting information on radiation belt products (models, datasets, events) that are useful to the community, in line with the deliverables outlined in our focus group proposal. We aim to collate this information and make it available to the community to facilitate collaboration across the radiation belts community. Examples of products that we aim to collect are datasets / models that can be used to study radiation belt dynamics and contact information of an expert who can be contacted for assistance with that data / model, specific events that you would like to highlight to the community, empirical models related to radiation belt dynamics, etc. If you would like to contribute to this database, please fill out this form: https://docs.google.com/forms/d/e/1FAIpQLSe5OpyJcP-A8Nd6_UNMEw4ZzzjGMov7wpRS0VTeCJEK54GMZA/viewform.

A list of products is available at: https://docs.google.com/spreadsheets/d/1lgc9SX86pXty5XQSFJA-YYt1l_lqT_KnAVfHepixmzY/edit?usp=sharing (navigate the tabs below to see different types).

== VERSIM x GEM Journal Club ==

The RB-SoS focus group is collaborating with VERSIM representatives to organise a journal club, which is held online on the first Wednesday of each month. Our goal is to create a friendly and lively environment where students can learn and engage, and build their scientific confidence. Information on the journal club (including the speaker schedule and zoom information) is available at https://aurora.troja.mff.cuni.cz/versim/index_jc.html.

== Mini-GEM 2025 ==

=== Schedule ===

The RB-SoS focus group will organise one session at the 2025 mini-GEM workshop. This will be held at 13:45 - 15:15 in room 383-385.

{| class="wikitable"
!#!! Time !! Presentations
|-
|1 ||13:45 || Louis Ozeke "A new database of large amplitude EMIC waves detected by the SWARM spacecraft"
|-
|2||13:55 || Xiaofei Shi "Statistical properties of quasi-periodic electron precipitation"
|-
|3||14:05 || Hong Zhao "Ultrarelativistic electron acceleration: Are satellite observations enough to identify the leading mechanism?"
|-
|4||14:15 || Hong Zhao "Bridging the radiation belt and ring current: new insights into energetic particle deep injection"
|-
|5||14:25 || Sergei Kamaletdinov "Energetic Electron Outward Radial Transport driven by Drift-Orbit Bifurcation"
|-
|6||14:35 || Alexander Drozdov "Python tools: Rbamlib and MTH5 Electric field data in PySPEDAS"
|-
|7||14:45 || Jay Albert "Resolution of the Greg Cunningham/quasilinear theory issue"
|-
|8||14:55 || Jay Albert "A model of Lauren Blum's periodic microburst observations"
|-
|9||15:05 || FG chairs: closing remarks
|-
|}

== Joint GEM / CEDAR Workshop 2025 ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== 6/24/2024 (Tue) ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== 6/25/2024 (Wed) ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|}

Remaining time for discussion.

=== 6/26/2024 (Thu) ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== 6/27/2024 (Fri) ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Harriet George,''' Institutet för rymdfysik (IRF) / Swedish Institute for Space Physics, harriet.george@irf.se
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Longzhi Gan''', Center for Space Physics, Boston University, lzgan@bu.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu (former chair).

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2026-07-07T17:14:45Z

RB-SoS: /* 7/14/2026 (Tue) */

== GEM workshop 2026 ==

=== Soliciting contributions ===

The RB-SoS focus group is currently soliciting presentations for the 2026 GEM workshop. The RB-SoS focus group is organising five sessions: three stand alone sessions, one joint session with the MPEC focus group, and one joint session with the KiTs, MESO and MAC focus groups.

The topics of these sessions are:
# Stand alone session 1: General contributions related to radiation belt dynamics.
# Stand alone session 2: Cross-population coupling in the inner magnetosphere, e.g. the coupling between the radiation belts and plasmasphere or ring current.
# Stand alone session 3: Event specific dynamics and variability between events, such as evaluating the role of adiabatic vs. non-adiabatic dynamics, radiation belt preconditioning or substorm level during case studies.
# RB-SoS / MPEC joint session: Radiation belt particle precipitation and its drivers, and the ionospheric impacts of this precipitation
# RB-SoS / KiTs / MESO / MAC joint session: Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere, with emphasis on near-Earth reconnection, particle injections, radiation-belt transport, and MI coupling.

To request a presentation in one of these sessions, please fill out this form https://forms.gle/7dBHBybMbr5VwxjV7 by July 6.

The RB-SoS is organising 5 sessions at the 2026 workshop; three stand-alone sessions and two joint sessions.
=== 7/13/2026 (Mon) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': Event specific dynamics and variability between events [12-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Karen Júlia Coldebella Ferreira "Competing Mechanisms of Relativistic Electron Flux Dropout and Low Flux Maintenance During a Long Duration Sheath Region: a Case Study"
|-
|2||1:50 || Man Hua "The Dominant role of the electron isotropy boundary in controlling Earth's outer radiation belt electron lifetimes"
|-
|3||2:05 || Misty Chien "Storm-Time Preconditioning and Adiabatic Transport of MeV Electrons Observed by CIRBE/REPTile-2"
|-
|4||2:20 || Kelly Cantwell "Time Evolution of Microburst Events with BARREL: X-ray Pulsations"
|-
|5||2:35 || Wesley Martin "Multi-Satellite Observations of SEP Proton Contributions to the Trapped Radiation Belt"
|}
Remaining time for discussion.

=== 7/14/2026 (Tue) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': General contributions [5-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:37 || Xinlin Li "Radiation Belt Dynamics from a Low Earth Orbit Perspective: New Insights from CIRBE/REPTile-2"
|-
|2||1:44 || Yang Mei "Atmospheric effects controlling Earth's inner radiation belt electrons unveiled by LEO satellite measurements and simulations"
|-
|3||1:51 || Frances Staples "Statistical Characterization of Radiation Belt Electron Acceleration Timescales Using Van Allen Probes and GPS Observations"
|-
|4||1:58 || Lauren Blum "ultra-relativistic electrons in the slot region following geomagnetic storms"
|-
|5||2:05 || David Malaspina "Inferring growth and propagation of whistler-mode waves in the radiation belts using power spectral density distributions"
|-
|6||2:12 || Huayue Chen "Chorus Element Repetition: Roles of Energetic Electron Injection and Nonlinear Wave Growth"
|-
|7||2:19 || Huayue Chen "Generation of Falling-Tone Whistler-Mode Chorus Waves in the Earth’s Magnetosphere"
|-
|8||2:26 || Greg Riggs "Understanding the Role of ULF Wave Latitude Distribution in Radiation Belt Electron Radial Diffusion"
|-
|9||2:33 || Jinbei Huang "Modeling Magnetopause Shadowing of Outer Radiation Belt Electrons: From Drift-Averaged Radial Diffusion to MLT-Resolved Drift Diffusion"
|-
|10||2:40 || Zhiyang Xia "Investigate the Effect of Plasma Density Perturbation on the Hiss Wave Amplitude"
|}
Remaining time for discussion.

=== 7/15/2024 (Wed) ===
*3:30 PM - 5 PM: '''RB SoS - MPEC joint session''': Radiation belt particle precipitation [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Myeong Joon Kim "Linear Instability Parameters Controlling Chorus Wave Modulation after the Onset of Pulsating Aurora"
|-
|2||1:55 || Qianli Ma "Modeling Radiation Belt Electron Fluxes Observed by ELFIN During the November 2021 Geomagnetic Storm"
|-
|3||2:15 || Alexander Drozdov "Intrinsic Hiss Waves and Their Role in Radiation Belt Dynamics"
|-
|4||2:35 || Zhi-Gu Li "Limits of the Bounce-Averaged Approximation: Pitch-Angle Diffusion and Electron Precipitation Near the Atmospheric Loss Cone"

|}
Remaining time for discussion.

=== 7/17/2026 (Fri) ===
*10:30 AM - 12 PM: '''RB SoS - topic session''': Cross-population coupling in the inner magnetosphere [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Ziye Zhang "The Role of the Plasmasphere in the Evolution of Reversed Radiation Belt Electron Energy Spectra."
|-
|2||1:55 || Taylor Whitney Aegerter "Electromagnetic Ion Cyclotron Waves in the Initial Phase of Geomagnetic Storms"
|-
|3||2:15 || Longzhi Gan "Bouncing Packets Driven by Ducted Lightning-Generated-Whistlers: Comparison with SAMPEX Observations"

|}
Remaining time for discussion.

*1:30 PM - 3 PM: '''RB SoS - KiTs - MESO - MAC joint session''': Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere
**''Please refer to the KiTs Focus Group''

== Community resources ==

We are soliciting information on radiation belt products (models, datasets, events) that are useful to the community, in line with the deliverables outlined in our focus group proposal. We aim to collate this information and make it available to the community to facilitate collaboration across the radiation belts community. Examples of products that we aim to collect are datasets / models that can be used to study radiation belt dynamics and contact information of an expert who can be contacted for assistance with that data / model, specific events that you would like to highlight to the community, empirical models related to radiation belt dynamics, etc. If you would like to contribute to this database, please fill out this form: https://docs.google.com/forms/d/e/1FAIpQLSe5OpyJcP-A8Nd6_UNMEw4ZzzjGMov7wpRS0VTeCJEK54GMZA/viewform.

A list of products is available at: https://docs.google.com/spreadsheets/d/1lgc9SX86pXty5XQSFJA-YYt1l_lqT_KnAVfHepixmzY/edit?usp=sharing (navigate the tabs below to see different types).

== VERSIM x GEM Journal Club ==

The RB-SoS focus group is collaborating with VERSIM representatives to organise a journal club, which is held online on the first Wednesday of each month. Our goal is to create a friendly and lively environment where students can learn and engage, and build their scientific confidence. Information on the journal club (including the speaker schedule and zoom information) is available at https://aurora.troja.mff.cuni.cz/versim/index_jc.html.

== Mini-GEM 2025 ==

=== Schedule ===

The RB-SoS focus group will organise one session at the 2025 mini-GEM workshop. This will be held at 13:45 - 15:15 in room 383-385.

{| class="wikitable"
!#!! Time !! Presentations
|-
|1 ||13:45 || Louis Ozeke "A new database of large amplitude EMIC waves detected by the SWARM spacecraft"
|-
|2||13:55 || Xiaofei Shi "Statistical properties of quasi-periodic electron precipitation"
|-
|3||14:05 || Hong Zhao "Ultrarelativistic electron acceleration: Are satellite observations enough to identify the leading mechanism?"
|-
|4||14:15 || Hong Zhao "Bridging the radiation belt and ring current: new insights into energetic particle deep injection"
|-
|5||14:25 || Sergei Kamaletdinov "Energetic Electron Outward Radial Transport driven by Drift-Orbit Bifurcation"
|-
|6||14:35 || Alexander Drozdov "Python tools: Rbamlib and MTH5 Electric field data in PySPEDAS"
|-
|7||14:45 || Jay Albert "Resolution of the Greg Cunningham/quasilinear theory issue"
|-
|8||14:55 || Jay Albert "A model of Lauren Blum's periodic microburst observations"
|-
|9||15:05 || FG chairs: closing remarks
|-
|}

== Joint GEM / CEDAR Workshop 2025 ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== 6/24/2024 (Tue) ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== 6/25/2024 (Wed) ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|}

Remaining time for discussion.

=== 6/26/2024 (Thu) ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== 6/27/2024 (Fri) ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Harriet George,''' Institutet för rymdfysik (IRF) / Swedish Institute for Space Physics, harriet.george@irf.se
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Longzhi Gan''', Center for Space Physics, Boston University, lzgan@bu.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu (former chair).

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2026-07-07T17:13:49Z

RB-SoS: /* 7/17/2026 (Fri) */

== GEM workshop 2026 ==

=== Soliciting contributions ===

The RB-SoS focus group is currently soliciting presentations for the 2026 GEM workshop. The RB-SoS focus group is organising five sessions: three stand alone sessions, one joint session with the MPEC focus group, and one joint session with the KiTs, MESO and MAC focus groups.

The topics of these sessions are:
# Stand alone session 1: General contributions related to radiation belt dynamics.
# Stand alone session 2: Cross-population coupling in the inner magnetosphere, e.g. the coupling between the radiation belts and plasmasphere or ring current.
# Stand alone session 3: Event specific dynamics and variability between events, such as evaluating the role of adiabatic vs. non-adiabatic dynamics, radiation belt preconditioning or substorm level during case studies.
# RB-SoS / MPEC joint session: Radiation belt particle precipitation and its drivers, and the ionospheric impacts of this precipitation
# RB-SoS / KiTs / MESO / MAC joint session: Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere, with emphasis on near-Earth reconnection, particle injections, radiation-belt transport, and MI coupling.

To request a presentation in one of these sessions, please fill out this form https://forms.gle/7dBHBybMbr5VwxjV7 by July 6.

The RB-SoS is organising 5 sessions at the 2026 workshop; three stand-alone sessions and two joint sessions.
=== 7/13/2026 (Mon) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': Event specific dynamics and variability between events [12-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Karen Júlia Coldebella Ferreira "Competing Mechanisms of Relativistic Electron Flux Dropout and Low Flux Maintenance During a Long Duration Sheath Region: a Case Study"
|-
|2||1:50 || Man Hua "The Dominant role of the electron isotropy boundary in controlling Earth's outer radiation belt electron lifetimes"
|-
|3||2:05 || Misty Chien "Storm-Time Preconditioning and Adiabatic Transport of MeV Electrons Observed by CIRBE/REPTile-2"
|-
|4||2:20 || Kelly Cantwell "Time Evolution of Microburst Events with BARREL: X-ray Pulsations"
|-
|5||2:35 || Wesley Martin "Multi-Satellite Observations of SEP Proton Contributions to the Trapped Radiation Belt"
|}
Remaining time for discussion.

=== 7/14/2026 (Tue) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': General contributions [5-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:37 || Xinlin Li "Radiation Belt Dynamics from a Low Earth Orbit Perspective: New Insights from CIRBE/REPTile-2"
|-
|2||1:44 || Yang Mei "Atmospheric effects controlling Earth's inner radiation belt electrons unveiled by LEO satellite measurements and simulations"
|-
|3||1:51 || Frances Staples "Statistical Characterization of Radiation Belt Electron Acceleration Timescales Using Van Allen Probes and GPS Observations"
|-
|4||1:58 || Lauren Blum "ultra-relativistic electrons in the slot region following geomagnetic storms"
|-
|5||2:05 || David Malaspina "Inferring growth and propagation of whistler-mode waves in the radiation belts using power spectral density distributions"
|-
|6||2:12 || Huayue Chen "Chorus Element Repetition: Roles of Energetic Electron Injection and Nonlinear Wave Growth"
|-
|7||2:19 || Huayue Chen "Generation of Falling-Tone Whistler-Mode Chorus Waves in the Earth’s Magnetosphere"
|-
|8||2:26 || Greg Riggs "Understanding the Role of ULF Wave Latitude Distribution in Radiation Belt Electron Radial Diffusion"
|-
|9||2:33 || Jinbei Huang "Modeling Magnetopause Shadowing of Outer Radiation Belt Electrons: From Drift-Averaged Radial Diffusion to MLT-Resolved Drift Diffusion"
|}
Remaining time for discussion.

=== 7/15/2024 (Wed) ===
*3:30 PM - 5 PM: '''RB SoS - MPEC joint session''': Radiation belt particle precipitation [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Myeong Joon Kim "Linear Instability Parameters Controlling Chorus Wave Modulation after the Onset of Pulsating Aurora"
|-
|2||1:55 || Qianli Ma "Modeling Radiation Belt Electron Fluxes Observed by ELFIN During the November 2021 Geomagnetic Storm"
|-
|3||2:15 || Alexander Drozdov "Intrinsic Hiss Waves and Their Role in Radiation Belt Dynamics"
|-
|4||2:35 || Zhi-Gu Li "Limits of the Bounce-Averaged Approximation: Pitch-Angle Diffusion and Electron Precipitation Near the Atmospheric Loss Cone"

|}
Remaining time for discussion.

=== 7/17/2026 (Fri) ===
*10:30 AM - 12 PM: '''RB SoS - topic session''': Cross-population coupling in the inner magnetosphere [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Ziye Zhang "The Role of the Plasmasphere in the Evolution of Reversed Radiation Belt Electron Energy Spectra."
|-
|2||1:55 || Taylor Whitney Aegerter "Electromagnetic Ion Cyclotron Waves in the Initial Phase of Geomagnetic Storms"
|-
|3||2:15 || Longzhi Gan "Bouncing Packets Driven by Ducted Lightning-Generated-Whistlers: Comparison with SAMPEX Observations"

|}
Remaining time for discussion.

*1:30 PM - 3 PM: '''RB SoS - KiTs - MESO - MAC joint session''': Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere
**''Please refer to the KiTs Focus Group''

== Community resources ==

We are soliciting information on radiation belt products (models, datasets, events) that are useful to the community, in line with the deliverables outlined in our focus group proposal. We aim to collate this information and make it available to the community to facilitate collaboration across the radiation belts community. Examples of products that we aim to collect are datasets / models that can be used to study radiation belt dynamics and contact information of an expert who can be contacted for assistance with that data / model, specific events that you would like to highlight to the community, empirical models related to radiation belt dynamics, etc. If you would like to contribute to this database, please fill out this form: https://docs.google.com/forms/d/e/1FAIpQLSe5OpyJcP-A8Nd6_UNMEw4ZzzjGMov7wpRS0VTeCJEK54GMZA/viewform.

A list of products is available at: https://docs.google.com/spreadsheets/d/1lgc9SX86pXty5XQSFJA-YYt1l_lqT_KnAVfHepixmzY/edit?usp=sharing (navigate the tabs below to see different types).

== VERSIM x GEM Journal Club ==

The RB-SoS focus group is collaborating with VERSIM representatives to organise a journal club, which is held online on the first Wednesday of each month. Our goal is to create a friendly and lively environment where students can learn and engage, and build their scientific confidence. Information on the journal club (including the speaker schedule and zoom information) is available at https://aurora.troja.mff.cuni.cz/versim/index_jc.html.

== Mini-GEM 2025 ==

=== Schedule ===

The RB-SoS focus group will organise one session at the 2025 mini-GEM workshop. This will be held at 13:45 - 15:15 in room 383-385.

{| class="wikitable"
!#!! Time !! Presentations
|-
|1 ||13:45 || Louis Ozeke "A new database of large amplitude EMIC waves detected by the SWARM spacecraft"
|-
|2||13:55 || Xiaofei Shi "Statistical properties of quasi-periodic electron precipitation"
|-
|3||14:05 || Hong Zhao "Ultrarelativistic electron acceleration: Are satellite observations enough to identify the leading mechanism?"
|-
|4||14:15 || Hong Zhao "Bridging the radiation belt and ring current: new insights into energetic particle deep injection"
|-
|5||14:25 || Sergei Kamaletdinov "Energetic Electron Outward Radial Transport driven by Drift-Orbit Bifurcation"
|-
|6||14:35 || Alexander Drozdov "Python tools: Rbamlib and MTH5 Electric field data in PySPEDAS"
|-
|7||14:45 || Jay Albert "Resolution of the Greg Cunningham/quasilinear theory issue"
|-
|8||14:55 || Jay Albert "A model of Lauren Blum's periodic microburst observations"
|-
|9||15:05 || FG chairs: closing remarks
|-
|}

== Joint GEM / CEDAR Workshop 2025 ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== 6/24/2024 (Tue) ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== 6/25/2024 (Wed) ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|}

Remaining time for discussion.

=== 6/26/2024 (Thu) ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== 6/27/2024 (Fri) ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Harriet George,''' Institutet för rymdfysik (IRF) / Swedish Institute for Space Physics, harriet.george@irf.se
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Longzhi Gan''', Center for Space Physics, Boston University, lzgan@bu.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu (former chair).

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2026-07-07T13:50:57Z

RB-SoS: /* Schedule */

== GEM workshop 2026 ==

=== Soliciting contributions ===

The RB-SoS focus group is currently soliciting presentations for the 2026 GEM workshop. The RB-SoS focus group is organising five sessions: three stand alone sessions, one joint session with the MPEC focus group, and one joint session with the KiTs, MESO and MAC focus groups.

The topics of these sessions are:
# Stand alone session 1: General contributions related to radiation belt dynamics.
# Stand alone session 2: Cross-population coupling in the inner magnetosphere, e.g. the coupling between the radiation belts and plasmasphere or ring current.
# Stand alone session 3: Event specific dynamics and variability between events, such as evaluating the role of adiabatic vs. non-adiabatic dynamics, radiation belt preconditioning or substorm level during case studies.
# RB-SoS / MPEC joint session: Radiation belt particle precipitation and its drivers, and the ionospheric impacts of this precipitation
# RB-SoS / KiTs / MESO / MAC joint session: Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere, with emphasis on near-Earth reconnection, particle injections, radiation-belt transport, and MI coupling.

To request a presentation in one of these sessions, please fill out this form https://forms.gle/7dBHBybMbr5VwxjV7 by July 6.

The RB-SoS is organising 5 sessions at the 2026 workshop; three stand-alone sessions and two joint sessions.
=== 7/13/2026 (Mon) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': Event specific dynamics and variability between events [12-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Karen Júlia Coldebella Ferreira "Competing Mechanisms of Relativistic Electron Flux Dropout and Low Flux Maintenance During a Long Duration Sheath Region: a Case Study"
|-
|2||1:50 || Man Hua "The Dominant role of the electron isotropy boundary in controlling Earth's outer radiation belt electron lifetimes"
|-
|3||2:05 || Misty Chien "Storm-Time Preconditioning and Adiabatic Transport of MeV Electrons Observed by CIRBE/REPTile-2"
|-
|4||2:20 || Kelly Cantwell "Time Evolution of Microburst Events with BARREL: X-ray Pulsations"
|-
|5||2:35 || Wesley Martin "Multi-Satellite Observations of SEP Proton Contributions to the Trapped Radiation Belt"
|}
Remaining time for discussion.

=== 7/14/2026 (Tue) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': General contributions [5-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:37 || Xinlin Li "Radiation Belt Dynamics from a Low Earth Orbit Perspective: New Insights from CIRBE/REPTile-2"
|-
|2||1:44 || Yang Mei "Atmospheric effects controlling Earth's inner radiation belt electrons unveiled by LEO satellite measurements and simulations"
|-
|3||1:51 || Frances Staples "Statistical Characterization of Radiation Belt Electron Acceleration Timescales Using Van Allen Probes and GPS Observations"
|-
|4||1:58 || Lauren Blum "ultra-relativistic electrons in the slot region following geomagnetic storms"
|-
|5||2:05 || David Malaspina "Inferring growth and propagation of whistler-mode waves in the radiation belts using power spectral density distributions"
|-
|6||2:12 || Huayue Chen "Chorus Element Repetition: Roles of Energetic Electron Injection and Nonlinear Wave Growth"
|-
|7||2:19 || Huayue Chen "Generation of Falling-Tone Whistler-Mode Chorus Waves in the Earth’s Magnetosphere"
|-
|8||2:26 || Greg Riggs "Understanding the Role of ULF Wave Latitude Distribution in Radiation Belt Electron Radial Diffusion"
|-
|9||2:33 || Jinbei Huang "Modeling Magnetopause Shadowing of Outer Radiation Belt Electrons: From Drift-Averaged Radial Diffusion to MLT-Resolved Drift Diffusion"
|}
Remaining time for discussion.

=== 7/15/2024 (Wed) ===
*3:30 PM - 5 PM: '''RB SoS - MPEC joint session''': Radiation belt particle precipitation [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Myeong Joon Kim "Linear Instability Parameters Controlling Chorus Wave Modulation after the Onset of Pulsating Aurora"
|-
|2||1:55 || Qianli Ma "Modeling Radiation Belt Electron Fluxes Observed by ELFIN During the November 2021 Geomagnetic Storm"
|-
|3||2:15 || Alexander Drozdov "Intrinsic Hiss Waves and Their Role in Radiation Belt Dynamics"
|-
|4||2:35 || Zhi-Gu Li "Limits of the Bounce-Averaged Approximation: Pitch-Angle Diffusion and Electron Precipitation Near the Atmospheric Loss Cone"

|}
Remaining time for discussion.

=== 7/17/2026 (Fri) ===
*10:30 AM - 12 PM: '''RB SoS - topic session''': Cross-population coupling in the inner magnetosphere [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Ziye Zhang "The Role of the Plasmasphere in the Evolution of Reversed Radiation Belt Electron Energy Spectra."
|-
|2||1:55 || Taylor Whitney Aegerter "Electromagnetic Ion Cyclotron Waves in the Initial Phase of Geomagnetic Storms"
|-
|3||2:15 || Zhiyang Xia "Investigate the Effect of Plasma Density Perturbation on the Hiss Wave Amplitude"
|-
|4||2:35 || Longzhi Gan "Bouncing Packets Driven by Ducted Lightning-Generated-Whistlers: Comparison with SAMPEX Observations"

|}
Remaining time for discussion.

*1:30 PM - 3 PM: '''RB SoS - KiTs - MESO - MAC joint session''': Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere
**''Please refer to the KiTs Focus Group''

== Community resources ==

We are soliciting information on radiation belt products (models, datasets, events) that are useful to the community, in line with the deliverables outlined in our focus group proposal. We aim to collate this information and make it available to the community to facilitate collaboration across the radiation belts community. Examples of products that we aim to collect are datasets / models that can be used to study radiation belt dynamics and contact information of an expert who can be contacted for assistance with that data / model, specific events that you would like to highlight to the community, empirical models related to radiation belt dynamics, etc. If you would like to contribute to this database, please fill out this form: https://docs.google.com/forms/d/e/1FAIpQLSe5OpyJcP-A8Nd6_UNMEw4ZzzjGMov7wpRS0VTeCJEK54GMZA/viewform.

A list of products is available at: https://docs.google.com/spreadsheets/d/1lgc9SX86pXty5XQSFJA-YYt1l_lqT_KnAVfHepixmzY/edit?usp=sharing (navigate the tabs below to see different types).

== VERSIM x GEM Journal Club ==

The RB-SoS focus group is collaborating with VERSIM representatives to organise a journal club, which is held online on the first Wednesday of each month. Our goal is to create a friendly and lively environment where students can learn and engage, and build their scientific confidence. Information on the journal club (including the speaker schedule and zoom information) is available at https://aurora.troja.mff.cuni.cz/versim/index_jc.html.

== Mini-GEM 2025 ==

=== Schedule ===

The RB-SoS focus group will organise one session at the 2025 mini-GEM workshop. This will be held at 13:45 - 15:15 in room 383-385.

{| class="wikitable"
!#!! Time !! Presentations
|-
|1 ||13:45 || Louis Ozeke "A new database of large amplitude EMIC waves detected by the SWARM spacecraft"
|-
|2||13:55 || Xiaofei Shi "Statistical properties of quasi-periodic electron precipitation"
|-
|3||14:05 || Hong Zhao "Ultrarelativistic electron acceleration: Are satellite observations enough to identify the leading mechanism?"
|-
|4||14:15 || Hong Zhao "Bridging the radiation belt and ring current: new insights into energetic particle deep injection"
|-
|5||14:25 || Sergei Kamaletdinov "Energetic Electron Outward Radial Transport driven by Drift-Orbit Bifurcation"
|-
|6||14:35 || Alexander Drozdov "Python tools: Rbamlib and MTH5 Electric field data in PySPEDAS"
|-
|7||14:45 || Jay Albert "Resolution of the Greg Cunningham/quasilinear theory issue"
|-
|8||14:55 || Jay Albert "A model of Lauren Blum's periodic microburst observations"
|-
|9||15:05 || FG chairs: closing remarks
|-
|}

== Joint GEM / CEDAR Workshop 2025 ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== 6/24/2024 (Tue) ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== 6/25/2024 (Wed) ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|}

Remaining time for discussion.

=== 6/26/2024 (Thu) ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== 6/27/2024 (Fri) ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Harriet George,''' Institutet för rymdfysik (IRF) / Swedish Institute for Space Physics, harriet.george@irf.se
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Longzhi Gan''', Center for Space Physics, Boston University, lzgan@bu.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu (former chair).

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2026-07-07T13:49:52Z

RB-SoS: /* Chairs */

== GEM workshop 2026 ==

=== Soliciting contributions ===

The RB-SoS focus group is currently soliciting presentations for the 2026 GEM workshop. The RB-SoS focus group is organising five sessions: three stand alone sessions, one joint session with the MPEC focus group, and one joint session with the KiTs, MESO and MAC focus groups.

The topics of these sessions are:
# Stand alone session 1: General contributions related to radiation belt dynamics.
# Stand alone session 2: Cross-population coupling in the inner magnetosphere, e.g. the coupling between the radiation belts and plasmasphere or ring current.
# Stand alone session 3: Event specific dynamics and variability between events, such as evaluating the role of adiabatic vs. non-adiabatic dynamics, radiation belt preconditioning or substorm level during case studies.
# RB-SoS / MPEC joint session: Radiation belt particle precipitation and its drivers, and the ionospheric impacts of this precipitation
# RB-SoS / KiTs / MESO / MAC joint session: Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere, with emphasis on near-Earth reconnection, particle injections, radiation-belt transport, and MI coupling.

To request a presentation in one of these sessions, please fill out this form https://forms.gle/7dBHBybMbr5VwxjV7 by July 6.

The RB-SoS is organising 5 sessions at the 2026 workshop; three stand-alone sessions and two joint sessions.
=== Schedule ===
=== 7/13/2026 (Mon) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': Event specific dynamics and variability between events [12-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Karen Júlia Coldebella Ferreira "Competing Mechanisms of Relativistic Electron Flux Dropout and Low Flux Maintenance During a Long Duration Sheath Region: a Case Study"
|-
|2||1:50 || Man Hua "The Dominant role of the electron isotropy boundary in controlling Earth's outer radiation belt electron lifetimes"
|-
|3||2:05 || Misty Chien "Storm-Time Preconditioning and Adiabatic Transport of MeV Electrons Observed by CIRBE/REPTile-2"
|-
|4||2:20 || Kelly Cantwell "Time Evolution of Microburst Events with BARREL: X-ray Pulsations"
|-
|5||2:35 || Wesley Martin "Multi-Satellite Observations of SEP Proton Contributions to the Trapped Radiation Belt"
|}
Remaining time for discussion.

=== 7/14/2026 (Tue) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': General contributions [5-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:37 || Xinlin Li "Radiation Belt Dynamics from a Low Earth Orbit Perspective: New Insights from CIRBE/REPTile-2"
|-
|2||1:44 || Yang Mei "Atmospheric effects controlling Earth's inner radiation belt electrons unveiled by LEO satellite measurements and simulations"
|-
|3||1:51 || Frances Staples "Statistical Characterization of Radiation Belt Electron Acceleration Timescales Using Van Allen Probes and GPS Observations"
|-
|4||1:58 || Lauren Blum "ultra-relativistic electrons in the slot region following geomagnetic storms"
|-
|5||2:05 || David Malaspina "Inferring growth and propagation of whistler-mode waves in the radiation belts using power spectral density distributions"
|-
|6||2:12 || Huayue Chen "Chorus Element Repetition: Roles of Energetic Electron Injection and Nonlinear Wave Growth"
|-
|7||2:19 || Huayue Chen "Generation of Falling-Tone Whistler-Mode Chorus Waves in the Earth’s Magnetosphere"
|-
|8||2:26 || Greg Riggs "Understanding the Role of ULF Wave Latitude Distribution in Radiation Belt Electron Radial Diffusion"
|-
|9||2:33 || Jinbei Huang "Modeling Magnetopause Shadowing of Outer Radiation Belt Electrons: From Drift-Averaged Radial Diffusion to MLT-Resolved Drift Diffusion"
|}
Remaining time for discussion.

=== 7/15/2024 (Wed) ===
*3:30 PM - 5 PM: '''RB SoS - MPEC joint session''': Radiation belt particle precipitation [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Myeong Joon Kim "Linear Instability Parameters Controlling Chorus Wave Modulation after the Onset of Pulsating Aurora"
|-
|2||1:55 || Qianli Ma "Modeling Radiation Belt Electron Fluxes Observed by ELFIN During the November 2021 Geomagnetic Storm"
|-
|3||2:15 || Alexander Drozdov "Intrinsic Hiss Waves and Their Role in Radiation Belt Dynamics"
|-
|4||2:35 || Zhi-Gu Li "Limits of the Bounce-Averaged Approximation: Pitch-Angle Diffusion and Electron Precipitation Near the Atmospheric Loss Cone"

|}
Remaining time for discussion.

=== 7/17/2026 (Fri) ===
*10:30 AM - 12 PM: '''RB SoS - topic session''': Cross-population coupling in the inner magnetosphere [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Ziye Zhang "The Role of the Plasmasphere in the Evolution of Reversed Radiation Belt Electron Energy Spectra."
|-
|2||1:55 || Taylor Whitney Aegerter "Electromagnetic Ion Cyclotron Waves in the Initial Phase of Geomagnetic Storms"
|-
|3||2:15 || Zhiyang Xia "Investigate the Effect of Plasma Density Perturbation on the Hiss Wave Amplitude"
|-
|4||2:35 || Longzhi Gan "Bouncing Packets Driven by Ducted Lightning-Generated-Whistlers: Comparison with SAMPEX Observations"

|}
Remaining time for discussion.

*1:30 PM - 3 PM: '''RB SoS - KiTs - MESO - MAC joint session''': Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere
**''Please refer to the KiTs Focus Group''

== Community resources ==

We are soliciting information on radiation belt products (models, datasets, events) that are useful to the community, in line with the deliverables outlined in our focus group proposal. We aim to collate this information and make it available to the community to facilitate collaboration across the radiation belts community. Examples of products that we aim to collect are datasets / models that can be used to study radiation belt dynamics and contact information of an expert who can be contacted for assistance with that data / model, specific events that you would like to highlight to the community, empirical models related to radiation belt dynamics, etc. If you would like to contribute to this database, please fill out this form: https://docs.google.com/forms/d/e/1FAIpQLSe5OpyJcP-A8Nd6_UNMEw4ZzzjGMov7wpRS0VTeCJEK54GMZA/viewform.

A list of products is available at: https://docs.google.com/spreadsheets/d/1lgc9SX86pXty5XQSFJA-YYt1l_lqT_KnAVfHepixmzY/edit?usp=sharing (navigate the tabs below to see different types).

== VERSIM x GEM Journal Club ==

The RB-SoS focus group is collaborating with VERSIM representatives to organise a journal club, which is held online on the first Wednesday of each month. Our goal is to create a friendly and lively environment where students can learn and engage, and build their scientific confidence. Information on the journal club (including the speaker schedule and zoom information) is available at https://aurora.troja.mff.cuni.cz/versim/index_jc.html.

== Mini-GEM 2025 ==

=== Schedule ===

The RB-SoS focus group will organise one session at the 2025 mini-GEM workshop. This will be held at 13:45 - 15:15 in room 383-385.

{| class="wikitable"
!#!! Time !! Presentations
|-
|1 ||13:45 || Louis Ozeke "A new database of large amplitude EMIC waves detected by the SWARM spacecraft"
|-
|2||13:55 || Xiaofei Shi "Statistical properties of quasi-periodic electron precipitation"
|-
|3||14:05 || Hong Zhao "Ultrarelativistic electron acceleration: Are satellite observations enough to identify the leading mechanism?"
|-
|4||14:15 || Hong Zhao "Bridging the radiation belt and ring current: new insights into energetic particle deep injection"
|-
|5||14:25 || Sergei Kamaletdinov "Energetic Electron Outward Radial Transport driven by Drift-Orbit Bifurcation"
|-
|6||14:35 || Alexander Drozdov "Python tools: Rbamlib and MTH5 Electric field data in PySPEDAS"
|-
|7||14:45 || Jay Albert "Resolution of the Greg Cunningham/quasilinear theory issue"
|-
|8||14:55 || Jay Albert "A model of Lauren Blum's periodic microburst observations"
|-
|9||15:05 || FG chairs: closing remarks
|-
|}

== Joint GEM / CEDAR Workshop 2025 ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== 6/24/2024 (Tue) ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== 6/25/2024 (Wed) ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|}

Remaining time for discussion.

=== 6/26/2024 (Thu) ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== 6/27/2024 (Fri) ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Harriet George,''' Institutet för rymdfysik (IRF) / Swedish Institute for Space Physics, harriet.george@irf.se
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Longzhi Gan''', Center for Space Physics, Boston University, lzgan@bu.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu (former chair).

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2026-07-07T13:45:23Z

RB-SoS: /* 7/17/2026 (Fri) */

== GEM workshop 2026 ==

=== Soliciting contributions ===

The RB-SoS focus group is currently soliciting presentations for the 2026 GEM workshop. The RB-SoS focus group is organising five sessions: three stand alone sessions, one joint session with the MPEC focus group, and one joint session with the KiTs, MESO and MAC focus groups.

The topics of these sessions are:
# Stand alone session 1: General contributions related to radiation belt dynamics.
# Stand alone session 2: Cross-population coupling in the inner magnetosphere, e.g. the coupling between the radiation belts and plasmasphere or ring current.
# Stand alone session 3: Event specific dynamics and variability between events, such as evaluating the role of adiabatic vs. non-adiabatic dynamics, radiation belt preconditioning or substorm level during case studies.
# RB-SoS / MPEC joint session: Radiation belt particle precipitation and its drivers, and the ionospheric impacts of this precipitation
# RB-SoS / KiTs / MESO / MAC joint session: Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere, with emphasis on near-Earth reconnection, particle injections, radiation-belt transport, and MI coupling.

To request a presentation in one of these sessions, please fill out this form https://forms.gle/7dBHBybMbr5VwxjV7 by July 6.

The RB-SoS is organising 5 sessions at the 2026 workshop; three stand-alone sessions and two joint sessions.
=== Schedule ===
=== 7/13/2026 (Mon) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': Event specific dynamics and variability between events [12-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Karen Júlia Coldebella Ferreira "Competing Mechanisms of Relativistic Electron Flux Dropout and Low Flux Maintenance During a Long Duration Sheath Region: a Case Study"
|-
|2||1:50 || Man Hua "The Dominant role of the electron isotropy boundary in controlling Earth's outer radiation belt electron lifetimes"
|-
|3||2:05 || Misty Chien "Storm-Time Preconditioning and Adiabatic Transport of MeV Electrons Observed by CIRBE/REPTile-2"
|-
|4||2:20 || Kelly Cantwell "Time Evolution of Microburst Events with BARREL: X-ray Pulsations"
|-
|5||2:35 || Wesley Martin "Multi-Satellite Observations of SEP Proton Contributions to the Trapped Radiation Belt"
|}
Remaining time for discussion.

=== 7/14/2026 (Tue) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': General contributions [5-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:37 || Xinlin Li "Radiation Belt Dynamics from a Low Earth Orbit Perspective: New Insights from CIRBE/REPTile-2"
|-
|2||1:44 || Yang Mei "Atmospheric effects controlling Earth's inner radiation belt electrons unveiled by LEO satellite measurements and simulations"
|-
|3||1:51 || Frances Staples "Statistical Characterization of Radiation Belt Electron Acceleration Timescales Using Van Allen Probes and GPS Observations"
|-
|4||1:58 || Lauren Blum "ultra-relativistic electrons in the slot region following geomagnetic storms"
|-
|5||2:05 || David Malaspina "Inferring growth and propagation of whistler-mode waves in the radiation belts using power spectral density distributions"
|-
|6||2:12 || Huayue Chen "Chorus Element Repetition: Roles of Energetic Electron Injection and Nonlinear Wave Growth"
|-
|7||2:19 || Huayue Chen "Generation of Falling-Tone Whistler-Mode Chorus Waves in the Earth’s Magnetosphere"
|-
|8||2:26 || Greg Riggs "Understanding the Role of ULF Wave Latitude Distribution in Radiation Belt Electron Radial Diffusion"
|-
|9||2:33 || Jinbei Huang "Modeling Magnetopause Shadowing of Outer Radiation Belt Electrons: From Drift-Averaged Radial Diffusion to MLT-Resolved Drift Diffusion"
|}
Remaining time for discussion.

=== 7/15/2024 (Wed) ===
*3:30 PM - 5 PM: '''RB SoS - MPEC joint session''': Radiation belt particle precipitation [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Myeong Joon Kim "Linear Instability Parameters Controlling Chorus Wave Modulation after the Onset of Pulsating Aurora"
|-
|2||1:55 || Qianli Ma "Modeling Radiation Belt Electron Fluxes Observed by ELFIN During the November 2021 Geomagnetic Storm"
|-
|3||2:15 || Alexander Drozdov "Intrinsic Hiss Waves and Their Role in Radiation Belt Dynamics"
|-
|4||2:35 || Zhi-Gu Li "Limits of the Bounce-Averaged Approximation: Pitch-Angle Diffusion and Electron Precipitation Near the Atmospheric Loss Cone"

|}
Remaining time for discussion.

=== 7/17/2026 (Fri) ===
*10:30 AM - 12 PM: '''RB SoS - topic session''': Cross-population coupling in the inner magnetosphere [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Ziye Zhang "The Role of the Plasmasphere in the Evolution of Reversed Radiation Belt Electron Energy Spectra."
|-
|2||1:55 || Taylor Whitney Aegerter "Electromagnetic Ion Cyclotron Waves in the Initial Phase of Geomagnetic Storms"
|-
|3||2:15 || Zhiyang Xia "Investigate the Effect of Plasma Density Perturbation on the Hiss Wave Amplitude"
|-
|4||2:35 || Longzhi Gan "Bouncing Packets Driven by Ducted Lightning-Generated-Whistlers: Comparison with SAMPEX Observations"

|}
Remaining time for discussion.

*1:30 PM - 3 PM: '''RB SoS - KiTs - MESO - MAC joint session''': Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere
**''Please refer to the KiTs Focus Group''

== Community resources ==

We are soliciting information on radiation belt products (models, datasets, events) that are useful to the community, in line with the deliverables outlined in our focus group proposal. We aim to collate this information and make it available to the community to facilitate collaboration across the radiation belts community. Examples of products that we aim to collect are datasets / models that can be used to study radiation belt dynamics and contact information of an expert who can be contacted for assistance with that data / model, specific events that you would like to highlight to the community, empirical models related to radiation belt dynamics, etc. If you would like to contribute to this database, please fill out this form: https://docs.google.com/forms/d/e/1FAIpQLSe5OpyJcP-A8Nd6_UNMEw4ZzzjGMov7wpRS0VTeCJEK54GMZA/viewform.

A list of products is available at: https://docs.google.com/spreadsheets/d/1lgc9SX86pXty5XQSFJA-YYt1l_lqT_KnAVfHepixmzY/edit?usp=sharing (navigate the tabs below to see different types).

== VERSIM x GEM Journal Club ==

The RB-SoS focus group is collaborating with VERSIM representatives to organise a journal club, which is held online on the first Wednesday of each month. Our goal is to create a friendly and lively environment where students can learn and engage, and build their scientific confidence. Information on the journal club (including the speaker schedule and zoom information) is available at https://aurora.troja.mff.cuni.cz/versim/index_jc.html.

== Mini-GEM 2025 ==

=== Schedule ===

The RB-SoS focus group will organise one session at the 2025 mini-GEM workshop. This will be held at 13:45 - 15:15 in room 383-385.

{| class="wikitable"
!#!! Time !! Presentations
|-
|1 ||13:45 || Louis Ozeke "A new database of large amplitude EMIC waves detected by the SWARM spacecraft"
|-
|2||13:55 || Xiaofei Shi "Statistical properties of quasi-periodic electron precipitation"
|-
|3||14:05 || Hong Zhao "Ultrarelativistic electron acceleration: Are satellite observations enough to identify the leading mechanism?"
|-
|4||14:15 || Hong Zhao "Bridging the radiation belt and ring current: new insights into energetic particle deep injection"
|-
|5||14:25 || Sergei Kamaletdinov "Energetic Electron Outward Radial Transport driven by Drift-Orbit Bifurcation"
|-
|6||14:35 || Alexander Drozdov "Python tools: Rbamlib and MTH5 Electric field data in PySPEDAS"
|-
|7||14:45 || Jay Albert "Resolution of the Greg Cunningham/quasilinear theory issue"
|-
|8||14:55 || Jay Albert "A model of Lauren Blum's periodic microburst observations"
|-
|9||15:05 || FG chairs: closing remarks
|-
|}

== Joint GEM / CEDAR Workshop 2025 ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== 6/24/2024 (Tue) ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== 6/25/2024 (Wed) ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|}

Remaining time for discussion.

=== 6/26/2024 (Thu) ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== 6/27/2024 (Fri) ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Longzhi Gan''', Center for Space Physics, Boston University, lzgan@bu.edu.
*'''Harriet George,''' Institutet för rymdfysik (IRF) / Swedish Institute for Space Physics, harriet.george@irf.se
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu (former chair).

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2026-07-07T13:40:12Z

RB-SoS: /* 7/17/2024 (Fri) */

== GEM workshop 2026 ==

=== Soliciting contributions ===

The RB-SoS focus group is currently soliciting presentations for the 2026 GEM workshop. The RB-SoS focus group is organising five sessions: three stand alone sessions, one joint session with the MPEC focus group, and one joint session with the KiTs, MESO and MAC focus groups.

The topics of these sessions are:
# Stand alone session 1: General contributions related to radiation belt dynamics.
# Stand alone session 2: Cross-population coupling in the inner magnetosphere, e.g. the coupling between the radiation belts and plasmasphere or ring current.
# Stand alone session 3: Event specific dynamics and variability between events, such as evaluating the role of adiabatic vs. non-adiabatic dynamics, radiation belt preconditioning or substorm level during case studies.
# RB-SoS / MPEC joint session: Radiation belt particle precipitation and its drivers, and the ionospheric impacts of this precipitation
# RB-SoS / KiTs / MESO / MAC joint session: Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere, with emphasis on near-Earth reconnection, particle injections, radiation-belt transport, and MI coupling.

To request a presentation in one of these sessions, please fill out this form https://forms.gle/7dBHBybMbr5VwxjV7 by July 6.

The RB-SoS is organising 5 sessions at the 2026 workshop; three stand-alone sessions and two joint sessions.
=== Schedule ===
=== 7/13/2026 (Mon) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': Event specific dynamics and variability between events [12-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Karen Júlia Coldebella Ferreira "Competing Mechanisms of Relativistic Electron Flux Dropout and Low Flux Maintenance During a Long Duration Sheath Region: a Case Study"
|-
|2||1:50 || Man Hua "The Dominant role of the electron isotropy boundary in controlling Earth's outer radiation belt electron lifetimes"
|-
|3||2:05 || Misty Chien "Storm-Time Preconditioning and Adiabatic Transport of MeV Electrons Observed by CIRBE/REPTile-2"
|-
|4||2:20 || Kelly Cantwell "Time Evolution of Microburst Events with BARREL: X-ray Pulsations"
|-
|5||2:35 || Wesley Martin "Multi-Satellite Observations of SEP Proton Contributions to the Trapped Radiation Belt"
|}
Remaining time for discussion.

=== 7/14/2026 (Tue) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': General contributions [5-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:37 || Xinlin Li "Radiation Belt Dynamics from a Low Earth Orbit Perspective: New Insights from CIRBE/REPTile-2"
|-
|2||1:44 || Yang Mei "Atmospheric effects controlling Earth's inner radiation belt electrons unveiled by LEO satellite measurements and simulations"
|-
|3||1:51 || Frances Staples "Statistical Characterization of Radiation Belt Electron Acceleration Timescales Using Van Allen Probes and GPS Observations"
|-
|4||1:58 || Lauren Blum "ultra-relativistic electrons in the slot region following geomagnetic storms"
|-
|5||2:05 || David Malaspina "Inferring growth and propagation of whistler-mode waves in the radiation belts using power spectral density distributions"
|-
|6||2:12 || Huayue Chen "Chorus Element Repetition: Roles of Energetic Electron Injection and Nonlinear Wave Growth"
|-
|7||2:19 || Huayue Chen "Generation of Falling-Tone Whistler-Mode Chorus Waves in the Earth’s Magnetosphere"
|-
|8||2:26 || Greg Riggs "Understanding the Role of ULF Wave Latitude Distribution in Radiation Belt Electron Radial Diffusion"
|-
|9||2:33 || Jinbei Huang "Modeling Magnetopause Shadowing of Outer Radiation Belt Electrons: From Drift-Averaged Radial Diffusion to MLT-Resolved Drift Diffusion"
|}
Remaining time for discussion.

=== 7/15/2024 (Wed) ===
*3:30 PM - 5 PM: '''RB SoS - MPEC joint session''': Radiation belt particle precipitation [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Myeong Joon Kim "Linear Instability Parameters Controlling Chorus Wave Modulation after the Onset of Pulsating Aurora"
|-
|2||1:55 || Qianli Ma "Modeling Radiation Belt Electron Fluxes Observed by ELFIN During the November 2021 Geomagnetic Storm"
|-
|3||2:15 || Alexander Drozdov "Intrinsic Hiss Waves and Their Role in Radiation Belt Dynamics"
|-
|4||2:35 || Zhi-Gu Li "Limits of the Bounce-Averaged Approximation: Pitch-Angle Diffusion and Electron Precipitation Near the Atmospheric Loss Cone"

|}
Remaining time for discussion.

=== 7/17/2026 (Fri) ===
*10:30 AM - 12 PM: '''RB SoS - topic session''': Cross-population coupling in the inner magnetosphere [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Ziye Zhang "The Role of the Plasmasphere in the Evolution of Reversed Radiation Belt Electron Energy Spectra."
|-
|2||1:55 || Taylor Whitney Aegerter "Electromagnetic Ion Cyclotron Waves in the Initial Phase of Geomagnetic Storms"
|-
|3||2:15 || Zhiyang Xia "Investigate the Effect of Plasma Density Perturbation on the Hiss Wave Amplitude"
|-
|4||2:35 || Longzhi Gan "Bouncing Packets Driven by Ducted Lightning-Generated-Whistlers: Comparison with SAMPEX Observations"

|}
Remaining time for discussion.

*1:30 PM - 15 PM: '''RB SoS - KiTs - MESO - MAC joint session''': Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere
**''Please refer to the KiTs Focus Group''

== Community resources ==

We are soliciting information on radiation belt products (models, datasets, events) that are useful to the community, in line with the deliverables outlined in our focus group proposal. We aim to collate this information and make it available to the community to facilitate collaboration across the radiation belts community. Examples of products that we aim to collect are datasets / models that can be used to study radiation belt dynamics and contact information of an expert who can be contacted for assistance with that data / model, specific events that you would like to highlight to the community, empirical models related to radiation belt dynamics, etc. If you would like to contribute to this database, please fill out this form: https://docs.google.com/forms/d/e/1FAIpQLSe5OpyJcP-A8Nd6_UNMEw4ZzzjGMov7wpRS0VTeCJEK54GMZA/viewform.

A list of products is available at: https://docs.google.com/spreadsheets/d/1lgc9SX86pXty5XQSFJA-YYt1l_lqT_KnAVfHepixmzY/edit?usp=sharing (navigate the tabs below to see different types).

== VERSIM x GEM Journal Club ==

The RB-SoS focus group is collaborating with VERSIM representatives to organise a journal club, which is held online on the first Wednesday of each month. Our goal is to create a friendly and lively environment where students can learn and engage, and build their scientific confidence. Information on the journal club (including the speaker schedule and zoom information) is available at https://aurora.troja.mff.cuni.cz/versim/index_jc.html.

== Mini-GEM 2025 ==

=== Schedule ===

The RB-SoS focus group will organise one session at the 2025 mini-GEM workshop. This will be held at 13:45 - 15:15 in room 383-385.

{| class="wikitable"
!#!! Time !! Presentations
|-
|1 ||13:45 || Louis Ozeke "A new database of large amplitude EMIC waves detected by the SWARM spacecraft"
|-
|2||13:55 || Xiaofei Shi "Statistical properties of quasi-periodic electron precipitation"
|-
|3||14:05 || Hong Zhao "Ultrarelativistic electron acceleration: Are satellite observations enough to identify the leading mechanism?"
|-
|4||14:15 || Hong Zhao "Bridging the radiation belt and ring current: new insights into energetic particle deep injection"
|-
|5||14:25 || Sergei Kamaletdinov "Energetic Electron Outward Radial Transport driven by Drift-Orbit Bifurcation"
|-
|6||14:35 || Alexander Drozdov "Python tools: Rbamlib and MTH5 Electric field data in PySPEDAS"
|-
|7||14:45 || Jay Albert "Resolution of the Greg Cunningham/quasilinear theory issue"
|-
|8||14:55 || Jay Albert "A model of Lauren Blum's periodic microburst observations"
|-
|9||15:05 || FG chairs: closing remarks
|-
|}

== Joint GEM / CEDAR Workshop 2025 ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== 6/24/2024 (Tue) ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== 6/25/2024 (Wed) ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|}

Remaining time for discussion.

=== 6/26/2024 (Thu) ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== 6/27/2024 (Fri) ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Longzhi Gan''', Center for Space Physics, Boston University, lzgan@bu.edu.
*'''Harriet George,''' Institutet för rymdfysik (IRF) / Swedish Institute for Space Physics, harriet.george@irf.se
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu (former chair).

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2026-07-07T13:39:26Z

RB-SoS: /* 7/14/2026 (Tue) */

== GEM workshop 2026 ==

=== Soliciting contributions ===

The RB-SoS focus group is currently soliciting presentations for the 2026 GEM workshop. The RB-SoS focus group is organising five sessions: three stand alone sessions, one joint session with the MPEC focus group, and one joint session with the KiTs, MESO and MAC focus groups.

The topics of these sessions are:
# Stand alone session 1: General contributions related to radiation belt dynamics.
# Stand alone session 2: Cross-population coupling in the inner magnetosphere, e.g. the coupling between the radiation belts and plasmasphere or ring current.
# Stand alone session 3: Event specific dynamics and variability between events, such as evaluating the role of adiabatic vs. non-adiabatic dynamics, radiation belt preconditioning or substorm level during case studies.
# RB-SoS / MPEC joint session: Radiation belt particle precipitation and its drivers, and the ionospheric impacts of this precipitation
# RB-SoS / KiTs / MESO / MAC joint session: Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere, with emphasis on near-Earth reconnection, particle injections, radiation-belt transport, and MI coupling.

To request a presentation in one of these sessions, please fill out this form https://forms.gle/7dBHBybMbr5VwxjV7 by July 6.

The RB-SoS is organising 5 sessions at the 2026 workshop; three stand-alone sessions and two joint sessions.
=== Schedule ===
=== 7/13/2026 (Mon) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': Event specific dynamics and variability between events [12-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Karen Júlia Coldebella Ferreira "Competing Mechanisms of Relativistic Electron Flux Dropout and Low Flux Maintenance During a Long Duration Sheath Region: a Case Study"
|-
|2||1:50 || Man Hua "The Dominant role of the electron isotropy boundary in controlling Earth's outer radiation belt electron lifetimes"
|-
|3||2:05 || Misty Chien "Storm-Time Preconditioning and Adiabatic Transport of MeV Electrons Observed by CIRBE/REPTile-2"
|-
|4||2:20 || Kelly Cantwell "Time Evolution of Microburst Events with BARREL: X-ray Pulsations"
|-
|5||2:35 || Wesley Martin "Multi-Satellite Observations of SEP Proton Contributions to the Trapped Radiation Belt"
|}
Remaining time for discussion.

=== 7/14/2026 (Tue) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': General contributions [5-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:37 || Xinlin Li "Radiation Belt Dynamics from a Low Earth Orbit Perspective: New Insights from CIRBE/REPTile-2"
|-
|2||1:44 || Yang Mei "Atmospheric effects controlling Earth's inner radiation belt electrons unveiled by LEO satellite measurements and simulations"
|-
|3||1:51 || Frances Staples "Statistical Characterization of Radiation Belt Electron Acceleration Timescales Using Van Allen Probes and GPS Observations"
|-
|4||1:58 || Lauren Blum "ultra-relativistic electrons in the slot region following geomagnetic storms"
|-
|5||2:05 || David Malaspina "Inferring growth and propagation of whistler-mode waves in the radiation belts using power spectral density distributions"
|-
|6||2:12 || Huayue Chen "Chorus Element Repetition: Roles of Energetic Electron Injection and Nonlinear Wave Growth"
|-
|7||2:19 || Huayue Chen "Generation of Falling-Tone Whistler-Mode Chorus Waves in the Earth’s Magnetosphere"
|-
|8||2:26 || Greg Riggs "Understanding the Role of ULF Wave Latitude Distribution in Radiation Belt Electron Radial Diffusion"
|-
|9||2:33 || Jinbei Huang "Modeling Magnetopause Shadowing of Outer Radiation Belt Electrons: From Drift-Averaged Radial Diffusion to MLT-Resolved Drift Diffusion"
|}
Remaining time for discussion.

=== 7/15/2024 (Wed) ===
*3:30 PM - 5 PM: '''RB SoS - MPEC joint session''': Radiation belt particle precipitation [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Myeong Joon Kim "Linear Instability Parameters Controlling Chorus Wave Modulation after the Onset of Pulsating Aurora"
|-
|2||1:55 || Qianli Ma "Modeling Radiation Belt Electron Fluxes Observed by ELFIN During the November 2021 Geomagnetic Storm"
|-
|3||2:15 || Alexander Drozdov "Intrinsic Hiss Waves and Their Role in Radiation Belt Dynamics"
|-
|4||2:35 || Zhi-Gu Li "Limits of the Bounce-Averaged Approximation: Pitch-Angle Diffusion and Electron Precipitation Near the Atmospheric Loss Cone"

|}
Remaining time for discussion.

=== 7/17/2026 (Fri) ===
*10:30 AM - 12 PM: '''RB SoS - topic session''': Cross-population coupling in the inner magnetosphere [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Ziye Zhang "The Role of the Plasmasphere in the Evolution of Reversed Radiation Belt Electron Energy Spectra."
|-
|2||1:55 || Taylor Whitney Aegerter "Electromagnetic Ion Cyclotron Waves in the Initial Phase of Geomagnetic Storms"
|-
|3||2:15 || Zhiyang Xia "Investigate the Effect of Plasma Density Perturbation on the Hiss Wave Amplitude"
|-
|4||2:35 || Longzhi Gan "Bouncing Packets Driven by Ducted Lightning-Generated-Whistlers: Comparison with SAMPEX Observations"

|}
Remaining time for discussion.

=== 7/17/2024 (Fri) ===
*1:30 PM - 15 PM: '''RB SoS - KiTs - MESO - MAC joint session''': Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere
**''Please refer to the KiTs Focus Group''

== Community resources ==

We are soliciting information on radiation belt products (models, datasets, events) that are useful to the community, in line with the deliverables outlined in our focus group proposal. We aim to collate this information and make it available to the community to facilitate collaboration across the radiation belts community. Examples of products that we aim to collect are datasets / models that can be used to study radiation belt dynamics and contact information of an expert who can be contacted for assistance with that data / model, specific events that you would like to highlight to the community, empirical models related to radiation belt dynamics, etc. If you would like to contribute to this database, please fill out this form: https://docs.google.com/forms/d/e/1FAIpQLSe5OpyJcP-A8Nd6_UNMEw4ZzzjGMov7wpRS0VTeCJEK54GMZA/viewform.

A list of products is available at: https://docs.google.com/spreadsheets/d/1lgc9SX86pXty5XQSFJA-YYt1l_lqT_KnAVfHepixmzY/edit?usp=sharing (navigate the tabs below to see different types).

== VERSIM x GEM Journal Club ==

The RB-SoS focus group is collaborating with VERSIM representatives to organise a journal club, which is held online on the first Wednesday of each month. Our goal is to create a friendly and lively environment where students can learn and engage, and build their scientific confidence. Information on the journal club (including the speaker schedule and zoom information) is available at https://aurora.troja.mff.cuni.cz/versim/index_jc.html.

== Mini-GEM 2025 ==

=== Schedule ===

The RB-SoS focus group will organise one session at the 2025 mini-GEM workshop. This will be held at 13:45 - 15:15 in room 383-385.

{| class="wikitable"
!#!! Time !! Presentations
|-
|1 ||13:45 || Louis Ozeke "A new database of large amplitude EMIC waves detected by the SWARM spacecraft"
|-
|2||13:55 || Xiaofei Shi "Statistical properties of quasi-periodic electron precipitation"
|-
|3||14:05 || Hong Zhao "Ultrarelativistic electron acceleration: Are satellite observations enough to identify the leading mechanism?"
|-
|4||14:15 || Hong Zhao "Bridging the radiation belt and ring current: new insights into energetic particle deep injection"
|-
|5||14:25 || Sergei Kamaletdinov "Energetic Electron Outward Radial Transport driven by Drift-Orbit Bifurcation"
|-
|6||14:35 || Alexander Drozdov "Python tools: Rbamlib and MTH5 Electric field data in PySPEDAS"
|-
|7||14:45 || Jay Albert "Resolution of the Greg Cunningham/quasilinear theory issue"
|-
|8||14:55 || Jay Albert "A model of Lauren Blum's periodic microburst observations"
|-
|9||15:05 || FG chairs: closing remarks
|-
|}

== Joint GEM / CEDAR Workshop 2025 ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== 6/24/2024 (Tue) ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== 6/25/2024 (Wed) ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|}

Remaining time for discussion.

=== 6/26/2024 (Thu) ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== 6/27/2024 (Fri) ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Longzhi Gan''', Center for Space Physics, Boston University, lzgan@bu.edu.
*'''Harriet George,''' Institutet för rymdfysik (IRF) / Swedish Institute for Space Physics, harriet.george@irf.se
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu (former chair).

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2026-07-07T13:34:43Z

RB-SoS: /* 7/17/2026 (Fri) */

== GEM workshop 2026 ==

=== Soliciting contributions ===

The RB-SoS focus group is currently soliciting presentations for the 2026 GEM workshop. The RB-SoS focus group is organising five sessions: three stand alone sessions, one joint session with the MPEC focus group, and one joint session with the KiTs, MESO and MAC focus groups.

The topics of these sessions are:
# Stand alone session 1: General contributions related to radiation belt dynamics.
# Stand alone session 2: Cross-population coupling in the inner magnetosphere, e.g. the coupling between the radiation belts and plasmasphere or ring current.
# Stand alone session 3: Event specific dynamics and variability between events, such as evaluating the role of adiabatic vs. non-adiabatic dynamics, radiation belt preconditioning or substorm level during case studies.
# RB-SoS / MPEC joint session: Radiation belt particle precipitation and its drivers, and the ionospheric impacts of this precipitation
# RB-SoS / KiTs / MESO / MAC joint session: Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere, with emphasis on near-Earth reconnection, particle injections, radiation-belt transport, and MI coupling.

To request a presentation in one of these sessions, please fill out this form https://forms.gle/7dBHBybMbr5VwxjV7 by July 6.

The RB-SoS is organising 5 sessions at the 2026 workshop; three stand-alone sessions and two joint sessions.
=== Schedule ===
=== 7/13/2026 (Mon) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': Event specific dynamics and variability between events [12-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Karen Júlia Coldebella Ferreira "Competing Mechanisms of Relativistic Electron Flux Dropout and Low Flux Maintenance During a Long Duration Sheath Region: a Case Study"
|-
|2||1:50 || Man Hua "The Dominant role of the electron isotropy boundary in controlling Earth's outer radiation belt electron lifetimes"
|-
|3||2:05 || Misty Chien "Storm-Time Preconditioning and Adiabatic Transport of MeV Electrons Observed by CIRBE/REPTile-2"
|-
|4||2:20 || Kelly Cantwell "Time Evolution of Microburst Events with BARREL: X-ray Pulsations"
|-
|5||2:35 || Wesley Martin "Multi-Satellite Observations of SEP Proton Contributions to the Trapped Radiation Belt"
|}
Remaining time for discussion.

=== 7/14/2026 (Tue) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': General contributions [5-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:37 || Xinlin Li "RB Dynamics from a LEO: New Insights from CIRBE/REPTile-2"
|-
|2||1:44 || Yang Mei "Atmospheric effects controlling Earth's inner radiation belt electrons unveiled by LEO satellite measurements and simulations"
|-
|3||1:51 || Frances Staples "Statistical Characterization of RB Acceleration Timescales Using RBSP and GPS"
|-
|4||1:58 || Lauren Blum "ultra-relativistic electrons in the slot region following geomagnetic storms"
|-
|5||2:05 || David Malaspina "Inferring growth and propagation of whistler-mode waves iusing power spectral density distributions "
|-
|6||2:12 || Huayue Chen "Chorus Element Repetition: Roles of Energetic Electron Injection and Nonlinear Wave Growth"
|-
|7||2:19 || Huayue Chen "Generation of Falling-Tone Whistler-Mode Chorus Waves in the Earth’s Magnetosphere"
|-
|8||2:26 || Greg Riggs "Understanding the Role of ULF Wave Latitude Distribution in Radiation Belt Electron Radial Diffusion"
|-
|9||2:33 || Jinbei Huang "Modeling MP Shadowing using MLT-Resolved Drift Diffusion"
|}
Remaining time for discussion.

=== 7/15/2024 (Wed) ===
*3:30 PM - 5 PM: '''RB SoS - MPEC joint session''': Radiation belt particle precipitation [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Myeong Joon Kim "Linear Instability Parameters Controlling Chorus Wave Modulation after the Onset of Pulsating Aurora"
|-
|2||1:55 || Qianli Ma "Modeling Radiation Belt Electron Fluxes Observed by ELFIN During the November 2021 Geomagnetic Storm"
|-
|3||2:15 || Alexander Drozdov "Intrinsic Hiss Waves and Their Role in Radiation Belt Dynamics"
|-
|4||2:35 || Zhi-Gu Li "Limits of the Bounce-Averaged Approximation: Pitch-Angle Diffusion and Electron Precipitation Near the Atmospheric Loss Cone"

|}
Remaining time for discussion.

=== 7/17/2026 (Fri) ===
*10:30 AM - 12 PM: '''RB SoS - topic session''': Cross-population coupling in the inner magnetosphere [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Ziye Zhang "The Role of the Plasmasphere in the Evolution of Reversed Radiation Belt Electron Energy Spectra."
|-
|2||1:55 || Taylor Whitney Aegerter "Electromagnetic Ion Cyclotron Waves in the Initial Phase of Geomagnetic Storms"
|-
|3||2:15 || Zhiyang Xia "Investigate the Effect of Plasma Density Perturbation on the Hiss Wave Amplitude"
|-
|4||2:35 || Longzhi Gan "Bouncing Packets Driven by Ducted Lightning-Generated-Whistlers: Comparison with SAMPEX Observations"

|}
Remaining time for discussion.

=== 7/17/2024 (Fri) ===
*1:30 PM - 15 PM: '''RB SoS - KiTs - MESO - MAC joint session''': Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere
**''Please refer to the KiTs Focus Group''

== Community resources ==

We are soliciting information on radiation belt products (models, datasets, events) that are useful to the community, in line with the deliverables outlined in our focus group proposal. We aim to collate this information and make it available to the community to facilitate collaboration across the radiation belts community. Examples of products that we aim to collect are datasets / models that can be used to study radiation belt dynamics and contact information of an expert who can be contacted for assistance with that data / model, specific events that you would like to highlight to the community, empirical models related to radiation belt dynamics, etc. If you would like to contribute to this database, please fill out this form: https://docs.google.com/forms/d/e/1FAIpQLSe5OpyJcP-A8Nd6_UNMEw4ZzzjGMov7wpRS0VTeCJEK54GMZA/viewform.

A list of products is available at: https://docs.google.com/spreadsheets/d/1lgc9SX86pXty5XQSFJA-YYt1l_lqT_KnAVfHepixmzY/edit?usp=sharing (navigate the tabs below to see different types).

== VERSIM x GEM Journal Club ==

The RB-SoS focus group is collaborating with VERSIM representatives to organise a journal club, which is held online on the first Wednesday of each month. Our goal is to create a friendly and lively environment where students can learn and engage, and build their scientific confidence. Information on the journal club (including the speaker schedule and zoom information) is available at https://aurora.troja.mff.cuni.cz/versim/index_jc.html.

== Mini-GEM 2025 ==

=== Schedule ===

The RB-SoS focus group will organise one session at the 2025 mini-GEM workshop. This will be held at 13:45 - 15:15 in room 383-385.

{| class="wikitable"
!#!! Time !! Presentations
|-
|1 ||13:45 || Louis Ozeke "A new database of large amplitude EMIC waves detected by the SWARM spacecraft"
|-
|2||13:55 || Xiaofei Shi "Statistical properties of quasi-periodic electron precipitation"
|-
|3||14:05 || Hong Zhao "Ultrarelativistic electron acceleration: Are satellite observations enough to identify the leading mechanism?"
|-
|4||14:15 || Hong Zhao "Bridging the radiation belt and ring current: new insights into energetic particle deep injection"
|-
|5||14:25 || Sergei Kamaletdinov "Energetic Electron Outward Radial Transport driven by Drift-Orbit Bifurcation"
|-
|6||14:35 || Alexander Drozdov "Python tools: Rbamlib and MTH5 Electric field data in PySPEDAS"
|-
|7||14:45 || Jay Albert "Resolution of the Greg Cunningham/quasilinear theory issue"
|-
|8||14:55 || Jay Albert "A model of Lauren Blum's periodic microburst observations"
|-
|9||15:05 || FG chairs: closing remarks
|-
|}

== Joint GEM / CEDAR Workshop 2025 ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== 6/24/2024 (Tue) ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== 6/25/2024 (Wed) ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|}

Remaining time for discussion.

=== 6/26/2024 (Thu) ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== 6/27/2024 (Fri) ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Longzhi Gan''', Center for Space Physics, Boston University, lzgan@bu.edu.
*'''Harriet George,''' Institutet för rymdfysik (IRF) / Swedish Institute for Space Physics, harriet.george@irf.se
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu (former chair).

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2026-07-07T13:33:14Z

RB-SoS: /* 7/17/2026 (Fri) */

== GEM workshop 2026 ==

=== Soliciting contributions ===

The RB-SoS focus group is currently soliciting presentations for the 2026 GEM workshop. The RB-SoS focus group is organising five sessions: three stand alone sessions, one joint session with the MPEC focus group, and one joint session with the KiTs, MESO and MAC focus groups.

The topics of these sessions are:
# Stand alone session 1: General contributions related to radiation belt dynamics.
# Stand alone session 2: Cross-population coupling in the inner magnetosphere, e.g. the coupling between the radiation belts and plasmasphere or ring current.
# Stand alone session 3: Event specific dynamics and variability between events, such as evaluating the role of adiabatic vs. non-adiabatic dynamics, radiation belt preconditioning or substorm level during case studies.
# RB-SoS / MPEC joint session: Radiation belt particle precipitation and its drivers, and the ionospheric impacts of this precipitation
# RB-SoS / KiTs / MESO / MAC joint session: Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere, with emphasis on near-Earth reconnection, particle injections, radiation-belt transport, and MI coupling.

To request a presentation in one of these sessions, please fill out this form https://forms.gle/7dBHBybMbr5VwxjV7 by July 6.

The RB-SoS is organising 5 sessions at the 2026 workshop; three stand-alone sessions and two joint sessions.
=== Schedule ===
=== 7/13/2026 (Mon) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': Event specific dynamics and variability between events [12-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Karen Júlia Coldebella Ferreira "Competing Mechanisms of Relativistic Electron Flux Dropout and Low Flux Maintenance During a Long Duration Sheath Region: a Case Study"
|-
|2||1:50 || Man Hua "The Dominant role of the electron isotropy boundary in controlling Earth's outer radiation belt electron lifetimes"
|-
|3||2:05 || Misty Chien "Storm-Time Preconditioning and Adiabatic Transport of MeV Electrons Observed by CIRBE/REPTile-2"
|-
|4||2:20 || Kelly Cantwell "Time Evolution of Microburst Events with BARREL: X-ray Pulsations"
|-
|5||2:35 || Wesley Martin "Multi-Satellite Observations of SEP Proton Contributions to the Trapped Radiation Belt"
|}
Remaining time for discussion.

=== 7/14/2026 (Tue) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': General contributions [5-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:37 || Xinlin Li "RB Dynamics from a LEO: New Insights from CIRBE/REPTile-2"
|-
|2||1:44 || Yang Mei "Atmospheric effects controlling Earth's inner radiation belt electrons unveiled by LEO satellite measurements and simulations"
|-
|3||1:51 || Frances Staples "Statistical Characterization of RB Acceleration Timescales Using RBSP and GPS"
|-
|4||1:58 || Lauren Blum "ultra-relativistic electrons in the slot region following geomagnetic storms"
|-
|5||2:05 || David Malaspina "Inferring growth and propagation of whistler-mode waves iusing power spectral density distributions "
|-
|6||2:12 || Huayue Chen "Chorus Element Repetition: Roles of Energetic Electron Injection and Nonlinear Wave Growth"
|-
|7||2:19 || Huayue Chen "Generation of Falling-Tone Whistler-Mode Chorus Waves in the Earth’s Magnetosphere"
|-
|8||2:26 || Greg Riggs "Understanding the Role of ULF Wave Latitude Distribution in Radiation Belt Electron Radial Diffusion"
|-
|9||2:33 || Jinbei Huang "Modeling MP Shadowing using MLT-Resolved Drift Diffusion"
|}
Remaining time for discussion.

=== 7/15/2024 (Wed) ===
*3:30 PM - 5 PM: '''RB SoS - MPEC joint session''': Radiation belt particle precipitation [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Myeong Joon Kim "Linear Instability Parameters Controlling Chorus Wave Modulation after the Onset of Pulsating Aurora"
|-
|2||1:55 || Qianli Ma "Modeling Radiation Belt Electron Fluxes Observed by ELFIN During the November 2021 Geomagnetic Storm"
|-
|3||2:15 || Alexander Drozdov "Intrinsic Hiss Waves and Their Role in Radiation Belt Dynamics"
|-
|4||2:35 || Zhi-Gu Li "Limits of the Bounce-Averaged Approximation: Pitch-Angle Diffusion and Electron Precipitation Near the Atmospheric Loss Cone"

|}
Remaining time for discussion.

=== 7/17/2026 (Fri) ===
*10:30 AM - 12 PM: '''RB SoS - topic session''': Cross-population coupling in the inner magnetosphere [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Ziye Zhang "The Role of the Plasmasphere in the Evolution of Reversed Radiation Belt Electron Energy Spectra."
|-
|2||1:55 || Taylor Whitney Aegerter "Electromagnetic Ion Cyclotron Waves in the Initial Phase of Geomagnetic Storms"
|-
|3||2:15 || Zhiyang Xia "Investigate the Effect of Plasma Density Perturbation on the Hiss Wave Amplitude"
|-
|4||2:35 || Longzhi Gan "Bouncing Packets Driven by Ducted Lightning-Generated-Whistlers: Comparison with SAMPEX Observations"

|}
Remaining time for discussion.

== Community resources ==

We are soliciting information on radiation belt products (models, datasets, events) that are useful to the community, in line with the deliverables outlined in our focus group proposal. We aim to collate this information and make it available to the community to facilitate collaboration across the radiation belts community. Examples of products that we aim to collect are datasets / models that can be used to study radiation belt dynamics and contact information of an expert who can be contacted for assistance with that data / model, specific events that you would like to highlight to the community, empirical models related to radiation belt dynamics, etc. If you would like to contribute to this database, please fill out this form: https://docs.google.com/forms/d/e/1FAIpQLSe5OpyJcP-A8Nd6_UNMEw4ZzzjGMov7wpRS0VTeCJEK54GMZA/viewform.

A list of products is available at: https://docs.google.com/spreadsheets/d/1lgc9SX86pXty5XQSFJA-YYt1l_lqT_KnAVfHepixmzY/edit?usp=sharing (navigate the tabs below to see different types).

== VERSIM x GEM Journal Club ==

The RB-SoS focus group is collaborating with VERSIM representatives to organise a journal club, which is held online on the first Wednesday of each month. Our goal is to create a friendly and lively environment where students can learn and engage, and build their scientific confidence. Information on the journal club (including the speaker schedule and zoom information) is available at https://aurora.troja.mff.cuni.cz/versim/index_jc.html.

== Mini-GEM 2025 ==

=== Schedule ===

The RB-SoS focus group will organise one session at the 2025 mini-GEM workshop. This will be held at 13:45 - 15:15 in room 383-385.

{| class="wikitable"
!#!! Time !! Presentations
|-
|1 ||13:45 || Louis Ozeke "A new database of large amplitude EMIC waves detected by the SWARM spacecraft"
|-
|2||13:55 || Xiaofei Shi "Statistical properties of quasi-periodic electron precipitation"
|-
|3||14:05 || Hong Zhao "Ultrarelativistic electron acceleration: Are satellite observations enough to identify the leading mechanism?"
|-
|4||14:15 || Hong Zhao "Bridging the radiation belt and ring current: new insights into energetic particle deep injection"
|-
|5||14:25 || Sergei Kamaletdinov "Energetic Electron Outward Radial Transport driven by Drift-Orbit Bifurcation"
|-
|6||14:35 || Alexander Drozdov "Python tools: Rbamlib and MTH5 Electric field data in PySPEDAS"
|-
|7||14:45 || Jay Albert "Resolution of the Greg Cunningham/quasilinear theory issue"
|-
|8||14:55 || Jay Albert "A model of Lauren Blum's periodic microburst observations"
|-
|9||15:05 || FG chairs: closing remarks
|-
|}

== Joint GEM / CEDAR Workshop 2025 ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== 6/24/2024 (Tue) ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== 6/25/2024 (Wed) ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|}

Remaining time for discussion.

=== 6/26/2024 (Thu) ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== 6/27/2024 (Fri) ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Longzhi Gan''', Center for Space Physics, Boston University, lzgan@bu.edu.
*'''Harriet George,''' Institutet för rymdfysik (IRF) / Swedish Institute for Space Physics, harriet.george@irf.se
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu (former chair).

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2026-07-07T13:32:45Z

RB-SoS: /* 7/15/2024 (Wed) */

== GEM workshop 2026 ==

=== Soliciting contributions ===

The RB-SoS focus group is currently soliciting presentations for the 2026 GEM workshop. The RB-SoS focus group is organising five sessions: three stand alone sessions, one joint session with the MPEC focus group, and one joint session with the KiTs, MESO and MAC focus groups.

The topics of these sessions are:
# Stand alone session 1: General contributions related to radiation belt dynamics.
# Stand alone session 2: Cross-population coupling in the inner magnetosphere, e.g. the coupling between the radiation belts and plasmasphere or ring current.
# Stand alone session 3: Event specific dynamics and variability between events, such as evaluating the role of adiabatic vs. non-adiabatic dynamics, radiation belt preconditioning or substorm level during case studies.
# RB-SoS / MPEC joint session: Radiation belt particle precipitation and its drivers, and the ionospheric impacts of this precipitation
# RB-SoS / KiTs / MESO / MAC joint session: Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere, with emphasis on near-Earth reconnection, particle injections, radiation-belt transport, and MI coupling.

To request a presentation in one of these sessions, please fill out this form https://forms.gle/7dBHBybMbr5VwxjV7 by July 6.

The RB-SoS is organising 5 sessions at the 2026 workshop; three stand-alone sessions and two joint sessions.
=== Schedule ===
=== 7/13/2026 (Mon) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': Event specific dynamics and variability between events [12-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Karen Júlia Coldebella Ferreira "Competing Mechanisms of Relativistic Electron Flux Dropout and Low Flux Maintenance During a Long Duration Sheath Region: a Case Study"
|-
|2||1:50 || Man Hua "The Dominant role of the electron isotropy boundary in controlling Earth's outer radiation belt electron lifetimes"
|-
|3||2:05 || Misty Chien "Storm-Time Preconditioning and Adiabatic Transport of MeV Electrons Observed by CIRBE/REPTile-2"
|-
|4||2:20 || Kelly Cantwell "Time Evolution of Microburst Events with BARREL: X-ray Pulsations"
|-
|5||2:35 || Wesley Martin "Multi-Satellite Observations of SEP Proton Contributions to the Trapped Radiation Belt"
|}
Remaining time for discussion.

=== 7/14/2026 (Tue) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': General contributions [5-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:37 || Xinlin Li "RB Dynamics from a LEO: New Insights from CIRBE/REPTile-2"
|-
|2||1:44 || Yang Mei "Atmospheric effects controlling Earth's inner radiation belt electrons unveiled by LEO satellite measurements and simulations"
|-
|3||1:51 || Frances Staples "Statistical Characterization of RB Acceleration Timescales Using RBSP and GPS"
|-
|4||1:58 || Lauren Blum "ultra-relativistic electrons in the slot region following geomagnetic storms"
|-
|5||2:05 || David Malaspina "Inferring growth and propagation of whistler-mode waves iusing power spectral density distributions "
|-
|6||2:12 || Huayue Chen "Chorus Element Repetition: Roles of Energetic Electron Injection and Nonlinear Wave Growth"
|-
|7||2:19 || Huayue Chen "Generation of Falling-Tone Whistler-Mode Chorus Waves in the Earth’s Magnetosphere"
|-
|8||2:26 || Greg Riggs "Understanding the Role of ULF Wave Latitude Distribution in Radiation Belt Electron Radial Diffusion"
|-
|9||2:33 || Jinbei Huang "Modeling MP Shadowing using MLT-Resolved Drift Diffusion"
|}
Remaining time for discussion.

=== 7/15/2024 (Wed) ===
*3:30 PM - 5 PM: '''RB SoS - MPEC joint session''': Radiation belt particle precipitation [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Myeong Joon Kim "Linear Instability Parameters Controlling Chorus Wave Modulation after the Onset of Pulsating Aurora"
|-
|2||1:55 || Qianli Ma "Modeling Radiation Belt Electron Fluxes Observed by ELFIN During the November 2021 Geomagnetic Storm"
|-
|3||2:15 || Alexander Drozdov "Intrinsic Hiss Waves and Their Role in Radiation Belt Dynamics"
|-
|4||2:35 || Zhi-Gu Li "Limits of the Bounce-Averaged Approximation: Pitch-Angle Diffusion and Electron Precipitation Near the Atmospheric Loss Cone"

|}
Remaining time for discussion.

=== 7/17/2026 (Fri) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': Cross-population coupling in the inner magnetosphere [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Ziye Zhang "The Role of the Plasmasphere in the Evolution of Reversed Radiation Belt Electron Energy Spectra."
|-
|2||1:55 || Taylor Whitney Aegerter "Electromagnetic Ion Cyclotron Waves in the Initial Phase of Geomagnetic Storms"
|-
|3||2:15 || Zhiyang Xia "Investigate the Effect of Plasma Density Perturbation on the Hiss Wave Amplitude"
|-
|4||2:35 || Longzhi Gan "Bouncing Packets Driven by Ducted Lightning-Generated-Whistlers: Comparison with SAMPEX Observations"

|}
Remaining time for discussion.

== Community resources ==

We are soliciting information on radiation belt products (models, datasets, events) that are useful to the community, in line with the deliverables outlined in our focus group proposal. We aim to collate this information and make it available to the community to facilitate collaboration across the radiation belts community. Examples of products that we aim to collect are datasets / models that can be used to study radiation belt dynamics and contact information of an expert who can be contacted for assistance with that data / model, specific events that you would like to highlight to the community, empirical models related to radiation belt dynamics, etc. If you would like to contribute to this database, please fill out this form: https://docs.google.com/forms/d/e/1FAIpQLSe5OpyJcP-A8Nd6_UNMEw4ZzzjGMov7wpRS0VTeCJEK54GMZA/viewform.

A list of products is available at: https://docs.google.com/spreadsheets/d/1lgc9SX86pXty5XQSFJA-YYt1l_lqT_KnAVfHepixmzY/edit?usp=sharing (navigate the tabs below to see different types).

== VERSIM x GEM Journal Club ==

The RB-SoS focus group is collaborating with VERSIM representatives to organise a journal club, which is held online on the first Wednesday of each month. Our goal is to create a friendly and lively environment where students can learn and engage, and build their scientific confidence. Information on the journal club (including the speaker schedule and zoom information) is available at https://aurora.troja.mff.cuni.cz/versim/index_jc.html.

== Mini-GEM 2025 ==

=== Schedule ===

The RB-SoS focus group will organise one session at the 2025 mini-GEM workshop. This will be held at 13:45 - 15:15 in room 383-385.

{| class="wikitable"
!#!! Time !! Presentations
|-
|1 ||13:45 || Louis Ozeke "A new database of large amplitude EMIC waves detected by the SWARM spacecraft"
|-
|2||13:55 || Xiaofei Shi "Statistical properties of quasi-periodic electron precipitation"
|-
|3||14:05 || Hong Zhao "Ultrarelativistic electron acceleration: Are satellite observations enough to identify the leading mechanism?"
|-
|4||14:15 || Hong Zhao "Bridging the radiation belt and ring current: new insights into energetic particle deep injection"
|-
|5||14:25 || Sergei Kamaletdinov "Energetic Electron Outward Radial Transport driven by Drift-Orbit Bifurcation"
|-
|6||14:35 || Alexander Drozdov "Python tools: Rbamlib and MTH5 Electric field data in PySPEDAS"
|-
|7||14:45 || Jay Albert "Resolution of the Greg Cunningham/quasilinear theory issue"
|-
|8||14:55 || Jay Albert "A model of Lauren Blum's periodic microburst observations"
|-
|9||15:05 || FG chairs: closing remarks
|-
|}

== Joint GEM / CEDAR Workshop 2025 ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== 6/24/2024 (Tue) ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== 6/25/2024 (Wed) ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|}

Remaining time for discussion.

=== 6/26/2024 (Thu) ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== 6/27/2024 (Fri) ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Longzhi Gan''', Center for Space Physics, Boston University, lzgan@bu.edu.
*'''Harriet George,''' Institutet för rymdfysik (IRF) / Swedish Institute for Space Physics, harriet.george@irf.se
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu (former chair).

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2026-07-07T13:32:02Z

RB-SoS: /* 7/17/2026 (Fri) */

== GEM workshop 2026 ==

=== Soliciting contributions ===

The RB-SoS focus group is currently soliciting presentations for the 2026 GEM workshop. The RB-SoS focus group is organising five sessions: three stand alone sessions, one joint session with the MPEC focus group, and one joint session with the KiTs, MESO and MAC focus groups.

The topics of these sessions are:
# Stand alone session 1: General contributions related to radiation belt dynamics.
# Stand alone session 2: Cross-population coupling in the inner magnetosphere, e.g. the coupling between the radiation belts and plasmasphere or ring current.
# Stand alone session 3: Event specific dynamics and variability between events, such as evaluating the role of adiabatic vs. non-adiabatic dynamics, radiation belt preconditioning or substorm level during case studies.
# RB-SoS / MPEC joint session: Radiation belt particle precipitation and its drivers, and the ionospheric impacts of this precipitation
# RB-SoS / KiTs / MESO / MAC joint session: Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere, with emphasis on near-Earth reconnection, particle injections, radiation-belt transport, and MI coupling.

To request a presentation in one of these sessions, please fill out this form https://forms.gle/7dBHBybMbr5VwxjV7 by July 6.

The RB-SoS is organising 5 sessions at the 2026 workshop; three stand-alone sessions and two joint sessions.
=== Schedule ===
=== 7/13/2026 (Mon) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': Event specific dynamics and variability between events [12-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Karen Júlia Coldebella Ferreira "Competing Mechanisms of Relativistic Electron Flux Dropout and Low Flux Maintenance During a Long Duration Sheath Region: a Case Study"
|-
|2||1:50 || Man Hua "The Dominant role of the electron isotropy boundary in controlling Earth's outer radiation belt electron lifetimes"
|-
|3||2:05 || Misty Chien "Storm-Time Preconditioning and Adiabatic Transport of MeV Electrons Observed by CIRBE/REPTile-2"
|-
|4||2:20 || Kelly Cantwell "Time Evolution of Microburst Events with BARREL: X-ray Pulsations"
|-
|5||2:35 || Wesley Martin "Multi-Satellite Observations of SEP Proton Contributions to the Trapped Radiation Belt"
|}
Remaining time for discussion.

=== 7/14/2026 (Tue) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': General contributions [5-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:37 || Xinlin Li "RB Dynamics from a LEO: New Insights from CIRBE/REPTile-2"
|-
|2||1:44 || Yang Mei "Atmospheric effects controlling Earth's inner radiation belt electrons unveiled by LEO satellite measurements and simulations"
|-
|3||1:51 || Frances Staples "Statistical Characterization of RB Acceleration Timescales Using RBSP and GPS"
|-
|4||1:58 || Lauren Blum "ultra-relativistic electrons in the slot region following geomagnetic storms"
|-
|5||2:05 || David Malaspina "Inferring growth and propagation of whistler-mode waves iusing power spectral density distributions "
|-
|6||2:12 || Huayue Chen "Chorus Element Repetition: Roles of Energetic Electron Injection and Nonlinear Wave Growth"
|-
|7||2:19 || Huayue Chen "Generation of Falling-Tone Whistler-Mode Chorus Waves in the Earth’s Magnetosphere"
|-
|8||2:26 || Greg Riggs "Understanding the Role of ULF Wave Latitude Distribution in Radiation Belt Electron Radial Diffusion"
|-
|9||2:33 || Jinbei Huang "Modeling MP Shadowing using MLT-Resolved Drift Diffusion"
|}
Remaining time for discussion.

=== 7/15/2024 (Wed) ===
*3:30 PM - 5 PM: '''RB SoS - MPEC joint session''': Radiation belt particle precipitation
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Myeong Joon Kim "Linear Instability Parameters Controlling Chorus Wave Modulation after the Onset of Pulsating Aurora"
|-
|2||1:55 || Qianli Ma "Modeling Radiation Belt Electron Fluxes Observed by ELFIN During the November 2021 Geomagnetic Storm"
|-
|3||2:15 || Alexander Drozdov "Intrinsic Hiss Waves and Their Role in Radiation Belt Dynamics"
|-
|4||2:35 || Zhi-Gu Li "Limits of the Bounce-Averaged Approximation: Pitch-Angle Diffusion and Electron Precipitation Near the Atmospheric Loss Cone"

|}
Remaining time for discussion.

=== 7/17/2026 (Fri) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': Cross-population coupling in the inner magnetosphere [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Ziye Zhang "The Role of the Plasmasphere in the Evolution of Reversed Radiation Belt Electron Energy Spectra."
|-
|2||1:55 || Taylor Whitney Aegerter "Electromagnetic Ion Cyclotron Waves in the Initial Phase of Geomagnetic Storms"
|-
|3||2:15 || Zhiyang Xia "Investigate the Effect of Plasma Density Perturbation on the Hiss Wave Amplitude"
|-
|4||2:35 || Longzhi Gan "Bouncing Packets Driven by Ducted Lightning-Generated-Whistlers: Comparison with SAMPEX Observations"

|}
Remaining time for discussion.

== Community resources ==

We are soliciting information on radiation belt products (models, datasets, events) that are useful to the community, in line with the deliverables outlined in our focus group proposal. We aim to collate this information and make it available to the community to facilitate collaboration across the radiation belts community. Examples of products that we aim to collect are datasets / models that can be used to study radiation belt dynamics and contact information of an expert who can be contacted for assistance with that data / model, specific events that you would like to highlight to the community, empirical models related to radiation belt dynamics, etc. If you would like to contribute to this database, please fill out this form: https://docs.google.com/forms/d/e/1FAIpQLSe5OpyJcP-A8Nd6_UNMEw4ZzzjGMov7wpRS0VTeCJEK54GMZA/viewform.

A list of products is available at: https://docs.google.com/spreadsheets/d/1lgc9SX86pXty5XQSFJA-YYt1l_lqT_KnAVfHepixmzY/edit?usp=sharing (navigate the tabs below to see different types).

== VERSIM x GEM Journal Club ==

The RB-SoS focus group is collaborating with VERSIM representatives to organise a journal club, which is held online on the first Wednesday of each month. Our goal is to create a friendly and lively environment where students can learn and engage, and build their scientific confidence. Information on the journal club (including the speaker schedule and zoom information) is available at https://aurora.troja.mff.cuni.cz/versim/index_jc.html.

== Mini-GEM 2025 ==

=== Schedule ===

The RB-SoS focus group will organise one session at the 2025 mini-GEM workshop. This will be held at 13:45 - 15:15 in room 383-385.

{| class="wikitable"
!#!! Time !! Presentations
|-
|1 ||13:45 || Louis Ozeke "A new database of large amplitude EMIC waves detected by the SWARM spacecraft"
|-
|2||13:55 || Xiaofei Shi "Statistical properties of quasi-periodic electron precipitation"
|-
|3||14:05 || Hong Zhao "Ultrarelativistic electron acceleration: Are satellite observations enough to identify the leading mechanism?"
|-
|4||14:15 || Hong Zhao "Bridging the radiation belt and ring current: new insights into energetic particle deep injection"
|-
|5||14:25 || Sergei Kamaletdinov "Energetic Electron Outward Radial Transport driven by Drift-Orbit Bifurcation"
|-
|6||14:35 || Alexander Drozdov "Python tools: Rbamlib and MTH5 Electric field data in PySPEDAS"
|-
|7||14:45 || Jay Albert "Resolution of the Greg Cunningham/quasilinear theory issue"
|-
|8||14:55 || Jay Albert "A model of Lauren Blum's periodic microburst observations"
|-
|9||15:05 || FG chairs: closing remarks
|-
|}

== Joint GEM / CEDAR Workshop 2025 ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== 6/24/2024 (Tue) ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== 6/25/2024 (Wed) ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|}

Remaining time for discussion.

=== 6/26/2024 (Thu) ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== 6/27/2024 (Fri) ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Longzhi Gan''', Center for Space Physics, Boston University, lzgan@bu.edu.
*'''Harriet George,''' Institutet för rymdfysik (IRF) / Swedish Institute for Space Physics, harriet.george@irf.se
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu (former chair).

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2026-07-07T13:28:24Z

RB-SoS: /* 7/14/2026 (Tue) */

== GEM workshop 2026 ==

=== Soliciting contributions ===

The RB-SoS focus group is currently soliciting presentations for the 2026 GEM workshop. The RB-SoS focus group is organising five sessions: three stand alone sessions, one joint session with the MPEC focus group, and one joint session with the KiTs, MESO and MAC focus groups.

The topics of these sessions are:
# Stand alone session 1: General contributions related to radiation belt dynamics.
# Stand alone session 2: Cross-population coupling in the inner magnetosphere, e.g. the coupling between the radiation belts and plasmasphere or ring current.
# Stand alone session 3: Event specific dynamics and variability between events, such as evaluating the role of adiabatic vs. non-adiabatic dynamics, radiation belt preconditioning or substorm level during case studies.
# RB-SoS / MPEC joint session: Radiation belt particle precipitation and its drivers, and the ionospheric impacts of this precipitation
# RB-SoS / KiTs / MESO / MAC joint session: Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere, with emphasis on near-Earth reconnection, particle injections, radiation-belt transport, and MI coupling.

To request a presentation in one of these sessions, please fill out this form https://forms.gle/7dBHBybMbr5VwxjV7 by July 6.

The RB-SoS is organising 5 sessions at the 2026 workshop; three stand-alone sessions and two joint sessions.
=== Schedule ===
=== 7/13/2026 (Mon) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': Event specific dynamics and variability between events [12-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Karen Júlia Coldebella Ferreira "Competing Mechanisms of Relativistic Electron Flux Dropout and Low Flux Maintenance During a Long Duration Sheath Region: a Case Study"
|-
|2||1:50 || Man Hua "The Dominant role of the electron isotropy boundary in controlling Earth's outer radiation belt electron lifetimes"
|-
|3||2:05 || Misty Chien "Storm-Time Preconditioning and Adiabatic Transport of MeV Electrons Observed by CIRBE/REPTile-2"
|-
|4||2:20 || Kelly Cantwell "Time Evolution of Microburst Events with BARREL: X-ray Pulsations"
|-
|5||2:35 || Wesley Martin "Multi-Satellite Observations of SEP Proton Contributions to the Trapped Radiation Belt"
|}
Remaining time for discussion.

=== 7/14/2026 (Tue) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': General contributions [5-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:37 || Xinlin Li "RB Dynamics from a LEO: New Insights from CIRBE/REPTile-2"
|-
|2||1:44 || Yang Mei "Atmospheric effects controlling Earth's inner radiation belt electrons unveiled by LEO satellite measurements and simulations"
|-
|3||1:51 || Frances Staples "Statistical Characterization of RB Acceleration Timescales Using RBSP and GPS"
|-
|4||1:58 || Lauren Blum "ultra-relativistic electrons in the slot region following geomagnetic storms"
|-
|5||2:05 || David Malaspina "Inferring growth and propagation of whistler-mode waves iusing power spectral density distributions "
|-
|6||2:12 || Huayue Chen "Chorus Element Repetition: Roles of Energetic Electron Injection and Nonlinear Wave Growth"
|-
|7||2:19 || Huayue Chen "Generation of Falling-Tone Whistler-Mode Chorus Waves in the Earth’s Magnetosphere"
|-
|8||2:26 || Greg Riggs "Understanding the Role of ULF Wave Latitude Distribution in Radiation Belt Electron Radial Diffusion"
|-
|9||2:33 || Jinbei Huang "Modeling MP Shadowing using MLT-Resolved Drift Diffusion"
|}
Remaining time for discussion.

=== 7/17/2026 (Fri) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': Cross-population coupling in the inner magnetosphere [15-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Ziye Zhang "The Role of the Plasmasphere in the Evolution of Reversed Radiation Belt Electron Energy Spectra."
|-
|2||1:55 || Taylor Whitney Aegerter "Electromagnetic Ion Cyclotron Waves in the Initial Phase of Geomagnetic Storms"
|-
|3||2:15 || Zhiyang Xia "Investigate the Effect of Plasma Density Perturbation on the Hiss Wave Amplitude"
|-
|4||2:35 || Longzhi Gan "Bouncing Packets Driven by Ducted Lightning-Generated-Whistlers: Comparison with SAMPEX Observations"

|}
Remaining time for discussion.

== Community resources ==

We are soliciting information on radiation belt products (models, datasets, events) that are useful to the community, in line with the deliverables outlined in our focus group proposal. We aim to collate this information and make it available to the community to facilitate collaboration across the radiation belts community. Examples of products that we aim to collect are datasets / models that can be used to study radiation belt dynamics and contact information of an expert who can be contacted for assistance with that data / model, specific events that you would like to highlight to the community, empirical models related to radiation belt dynamics, etc. If you would like to contribute to this database, please fill out this form: https://docs.google.com/forms/d/e/1FAIpQLSe5OpyJcP-A8Nd6_UNMEw4ZzzjGMov7wpRS0VTeCJEK54GMZA/viewform.

A list of products is available at: https://docs.google.com/spreadsheets/d/1lgc9SX86pXty5XQSFJA-YYt1l_lqT_KnAVfHepixmzY/edit?usp=sharing (navigate the tabs below to see different types).

== VERSIM x GEM Journal Club ==

The RB-SoS focus group is collaborating with VERSIM representatives to organise a journal club, which is held online on the first Wednesday of each month. Our goal is to create a friendly and lively environment where students can learn and engage, and build their scientific confidence. Information on the journal club (including the speaker schedule and zoom information) is available at https://aurora.troja.mff.cuni.cz/versim/index_jc.html.

== Mini-GEM 2025 ==

=== Schedule ===

The RB-SoS focus group will organise one session at the 2025 mini-GEM workshop. This will be held at 13:45 - 15:15 in room 383-385.

{| class="wikitable"
!#!! Time !! Presentations
|-
|1 ||13:45 || Louis Ozeke "A new database of large amplitude EMIC waves detected by the SWARM spacecraft"
|-
|2||13:55 || Xiaofei Shi "Statistical properties of quasi-periodic electron precipitation"
|-
|3||14:05 || Hong Zhao "Ultrarelativistic electron acceleration: Are satellite observations enough to identify the leading mechanism?"
|-
|4||14:15 || Hong Zhao "Bridging the radiation belt and ring current: new insights into energetic particle deep injection"
|-
|5||14:25 || Sergei Kamaletdinov "Energetic Electron Outward Radial Transport driven by Drift-Orbit Bifurcation"
|-
|6||14:35 || Alexander Drozdov "Python tools: Rbamlib and MTH5 Electric field data in PySPEDAS"
|-
|7||14:45 || Jay Albert "Resolution of the Greg Cunningham/quasilinear theory issue"
|-
|8||14:55 || Jay Albert "A model of Lauren Blum's periodic microburst observations"
|-
|9||15:05 || FG chairs: closing remarks
|-
|}

== Joint GEM / CEDAR Workshop 2025 ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== 6/24/2024 (Tue) ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== 6/25/2024 (Wed) ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|}

Remaining time for discussion.

=== 6/26/2024 (Thu) ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== 6/27/2024 (Fri) ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Longzhi Gan''', Center for Space Physics, Boston University, lzgan@bu.edu.
*'''Harriet George,''' Institutet för rymdfysik (IRF) / Swedish Institute for Space Physics, harriet.george@irf.se
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu (former chair).

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2026-07-07T13:24:45Z

RB-SoS: /* 7/13/2026 (Mon) */

== GEM workshop 2026 ==

=== Soliciting contributions ===

The RB-SoS focus group is currently soliciting presentations for the 2026 GEM workshop. The RB-SoS focus group is organising five sessions: three stand alone sessions, one joint session with the MPEC focus group, and one joint session with the KiTs, MESO and MAC focus groups.

The topics of these sessions are:
# Stand alone session 1: General contributions related to radiation belt dynamics.
# Stand alone session 2: Cross-population coupling in the inner magnetosphere, e.g. the coupling between the radiation belts and plasmasphere or ring current.
# Stand alone session 3: Event specific dynamics and variability between events, such as evaluating the role of adiabatic vs. non-adiabatic dynamics, radiation belt preconditioning or substorm level during case studies.
# RB-SoS / MPEC joint session: Radiation belt particle precipitation and its drivers, and the ionospheric impacts of this precipitation
# RB-SoS / KiTs / MESO / MAC joint session: Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere, with emphasis on near-Earth reconnection, particle injections, radiation-belt transport, and MI coupling.

To request a presentation in one of these sessions, please fill out this form https://forms.gle/7dBHBybMbr5VwxjV7 by July 6.

The RB-SoS is organising 5 sessions at the 2026 workshop; three stand-alone sessions and two joint sessions.
=== Schedule ===
=== 7/13/2026 (Mon) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': Event specific dynamics and variability between events [12-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:35 || Karen Júlia Coldebella Ferreira "Competing Mechanisms of Relativistic Electron Flux Dropout and Low Flux Maintenance During a Long Duration Sheath Region: a Case Study"
|-
|2||1:50 || Man Hua "The Dominant role of the electron isotropy boundary in controlling Earth's outer radiation belt electron lifetimes"
|-
|3||2:05 || Misty Chien "Storm-Time Preconditioning and Adiabatic Transport of MeV Electrons Observed by CIRBE/REPTile-2"
|-
|4||2:20 || Kelly Cantwell "Time Evolution of Microburst Events with BARREL: X-ray Pulsations"
|-
|5||2:35 || Wesley Martin "Multi-Satellite Observations of SEP Proton Contributions to the Trapped Radiation Belt"
|}
Remaining time for discussion.

=== 7/14/2026 (Tue) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': General contributions [5-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:37 || Xinlin Li "RB Dynamics from a LEO: New Insights from CIRBE/REPTile-2"
|-
|2||1:44 || Yang Mei "Atmospheric effects controlling Earth's inner radiation belt electrons unveiled by LEO satellite measurements and simulations"
|-
|3||1:51 || Frances Staples "Statistical Characterization of RB Acceleration Timescales Using RBSP and GPS"
|-
|4||1:58 || Lauren Blum "ultra-relativistic electrons in the slot region following geomagnetic storms"
|-
|5||2:05 || David Malaspina "Inferring growth and propagation of whistler-mode waves iusing power spectral density distributions "
|-
|6||2:12 || Huayue Chen "Chorus Element Repetition: Roles of Energetic Electron Injection and Nonlinear Wave Growth"
|-
|7||2:19 || Huayue Chen "Generation of Falling-Tone Whistler-Mode Chorus Waves in the Earth’s Magnetosphere"
|-
|8||2:26 || Greg Riggs "Understanding the Role of ULF Wave Latitude Distribution in Radiation Belt Electron Radial Diffusion"
|-
|9||2:33 || Jinbei Huang "Modeling MP Shadowing using MLT-Resolved Drift Diffusion"
|}
Remaining time for discussion.

== Community resources ==

We are soliciting information on radiation belt products (models, datasets, events) that are useful to the community, in line with the deliverables outlined in our focus group proposal. We aim to collate this information and make it available to the community to facilitate collaboration across the radiation belts community. Examples of products that we aim to collect are datasets / models that can be used to study radiation belt dynamics and contact information of an expert who can be contacted for assistance with that data / model, specific events that you would like to highlight to the community, empirical models related to radiation belt dynamics, etc. If you would like to contribute to this database, please fill out this form: https://docs.google.com/forms/d/e/1FAIpQLSe5OpyJcP-A8Nd6_UNMEw4ZzzjGMov7wpRS0VTeCJEK54GMZA/viewform.

A list of products is available at: https://docs.google.com/spreadsheets/d/1lgc9SX86pXty5XQSFJA-YYt1l_lqT_KnAVfHepixmzY/edit?usp=sharing (navigate the tabs below to see different types).

== VERSIM x GEM Journal Club ==

The RB-SoS focus group is collaborating with VERSIM representatives to organise a journal club, which is held online on the first Wednesday of each month. Our goal is to create a friendly and lively environment where students can learn and engage, and build their scientific confidence. Information on the journal club (including the speaker schedule and zoom information) is available at https://aurora.troja.mff.cuni.cz/versim/index_jc.html.

== Mini-GEM 2025 ==

=== Schedule ===

The RB-SoS focus group will organise one session at the 2025 mini-GEM workshop. This will be held at 13:45 - 15:15 in room 383-385.

{| class="wikitable"
!#!! Time !! Presentations
|-
|1 ||13:45 || Louis Ozeke "A new database of large amplitude EMIC waves detected by the SWARM spacecraft"
|-
|2||13:55 || Xiaofei Shi "Statistical properties of quasi-periodic electron precipitation"
|-
|3||14:05 || Hong Zhao "Ultrarelativistic electron acceleration: Are satellite observations enough to identify the leading mechanism?"
|-
|4||14:15 || Hong Zhao "Bridging the radiation belt and ring current: new insights into energetic particle deep injection"
|-
|5||14:25 || Sergei Kamaletdinov "Energetic Electron Outward Radial Transport driven by Drift-Orbit Bifurcation"
|-
|6||14:35 || Alexander Drozdov "Python tools: Rbamlib and MTH5 Electric field data in PySPEDAS"
|-
|7||14:45 || Jay Albert "Resolution of the Greg Cunningham/quasilinear theory issue"
|-
|8||14:55 || Jay Albert "A model of Lauren Blum's periodic microburst observations"
|-
|9||15:05 || FG chairs: closing remarks
|-
|}

== Joint GEM / CEDAR Workshop 2025 ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== 6/24/2024 (Tue) ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== 6/25/2024 (Wed) ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|}

Remaining time for discussion.

=== 6/26/2024 (Thu) ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== 6/27/2024 (Fri) ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Longzhi Gan''', Center for Space Physics, Boston University, lzgan@bu.edu.
*'''Harriet George,''' Institutet för rymdfysik (IRF) / Swedish Institute for Space Physics, harriet.george@irf.se
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu (former chair).

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2026-07-07T13:21:39Z

RB-SoS: /* 7/13/2026 (Mon) */

== GEM workshop 2026 ==

=== Soliciting contributions ===

The RB-SoS focus group is currently soliciting presentations for the 2026 GEM workshop. The RB-SoS focus group is organising five sessions: three stand alone sessions, one joint session with the MPEC focus group, and one joint session with the KiTs, MESO and MAC focus groups.

The topics of these sessions are:
# Stand alone session 1: General contributions related to radiation belt dynamics.
# Stand alone session 2: Cross-population coupling in the inner magnetosphere, e.g. the coupling between the radiation belts and plasmasphere or ring current.
# Stand alone session 3: Event specific dynamics and variability between events, such as evaluating the role of adiabatic vs. non-adiabatic dynamics, radiation belt preconditioning or substorm level during case studies.
# RB-SoS / MPEC joint session: Radiation belt particle precipitation and its drivers, and the ionospheric impacts of this precipitation
# RB-SoS / KiTs / MESO / MAC joint session: Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere, with emphasis on near-Earth reconnection, particle injections, radiation-belt transport, and MI coupling.

To request a presentation in one of these sessions, please fill out this form https://forms.gle/7dBHBybMbr5VwxjV7 by July 6.

The RB-SoS is organising 5 sessions at the 2026 workshop; three stand-alone sessions and two joint sessions.
=== Schedule ===
=== 7/13/2026 (Mon) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': Event specific dynamics and variability between events [12-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:37 || Xinlin Li "RB Dynamics from a LEO: New Insights from CIRBE/REPTile-2"
|-
|2||1:44 || Yang Mei "Atmospheric effects controlling Earth's inner radiation belt electrons unveiled by LEO satellite measurements and simulations"
|-
|3||1:51 || Frances Staples "Statistical Characterization of RB Acceleration Timescales Using RBSP and GPS"
|-
|4||1:58 || Lauren Blum "ultra-relativistic electrons in the slot region following geomagnetic storms"
|-
|5||2:05 || David Malaspina "Inferring growth and propagation of whistler-mode waves iusing power spectral density distributions "
|-
|6||2:12 || Huayue Chen "Chorus Element Repetition: Roles of Energetic Electron Injection and Nonlinear Wave Growth"
|-
|7||2:19 || Huayue Chen "Generation of Falling-Tone Whistler-Mode Chorus Waves in the Earth’s Magnetosphere"
|-
|8||2:26 || Greg Riggs "Understanding the Role of ULF Wave Latitude Distribution in Radiation Belt Electron Radial Diffusion"
|-
|9||2:33 || Jinbei Huang "Modeling MP Shadowing using MLT-Resolved Drift Diffusion"
|}
Remaining time for discussion.

=== 7/14/2026 (Tue) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': General contributions [5-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:37 || Xinlin Li "RB Dynamics from a LEO: New Insights from CIRBE/REPTile-2"
|-
|2||1:44 || Yang Mei "Atmospheric effects controlling Earth's inner radiation belt electrons unveiled by LEO satellite measurements and simulations"
|-
|3||1:51 || Frances Staples "Statistical Characterization of RB Acceleration Timescales Using RBSP and GPS"
|-
|4||1:58 || Lauren Blum "ultra-relativistic electrons in the slot region following geomagnetic storms"
|-
|5||2:05 || David Malaspina "Inferring growth and propagation of whistler-mode waves iusing power spectral density distributions "
|-
|6||2:12 || Huayue Chen "Chorus Element Repetition: Roles of Energetic Electron Injection and Nonlinear Wave Growth"
|-
|7||2:19 || Huayue Chen "Generation of Falling-Tone Whistler-Mode Chorus Waves in the Earth’s Magnetosphere"
|-
|8||2:26 || Greg Riggs "Understanding the Role of ULF Wave Latitude Distribution in Radiation Belt Electron Radial Diffusion"
|-
|9||2:33 || Jinbei Huang "Modeling MP Shadowing using MLT-Resolved Drift Diffusion"
|}
Remaining time for discussion.

== Community resources ==

We are soliciting information on radiation belt products (models, datasets, events) that are useful to the community, in line with the deliverables outlined in our focus group proposal. We aim to collate this information and make it available to the community to facilitate collaboration across the radiation belts community. Examples of products that we aim to collect are datasets / models that can be used to study radiation belt dynamics and contact information of an expert who can be contacted for assistance with that data / model, specific events that you would like to highlight to the community, empirical models related to radiation belt dynamics, etc. If you would like to contribute to this database, please fill out this form: https://docs.google.com/forms/d/e/1FAIpQLSe5OpyJcP-A8Nd6_UNMEw4ZzzjGMov7wpRS0VTeCJEK54GMZA/viewform.

A list of products is available at: https://docs.google.com/spreadsheets/d/1lgc9SX86pXty5XQSFJA-YYt1l_lqT_KnAVfHepixmzY/edit?usp=sharing (navigate the tabs below to see different types).

== VERSIM x GEM Journal Club ==

The RB-SoS focus group is collaborating with VERSIM representatives to organise a journal club, which is held online on the first Wednesday of each month. Our goal is to create a friendly and lively environment where students can learn and engage, and build their scientific confidence. Information on the journal club (including the speaker schedule and zoom information) is available at https://aurora.troja.mff.cuni.cz/versim/index_jc.html.

== Mini-GEM 2025 ==

=== Schedule ===

The RB-SoS focus group will organise one session at the 2025 mini-GEM workshop. This will be held at 13:45 - 15:15 in room 383-385.

{| class="wikitable"
!#!! Time !! Presentations
|-
|1 ||13:45 || Louis Ozeke "A new database of large amplitude EMIC waves detected by the SWARM spacecraft"
|-
|2||13:55 || Xiaofei Shi "Statistical properties of quasi-periodic electron precipitation"
|-
|3||14:05 || Hong Zhao "Ultrarelativistic electron acceleration: Are satellite observations enough to identify the leading mechanism?"
|-
|4||14:15 || Hong Zhao "Bridging the radiation belt and ring current: new insights into energetic particle deep injection"
|-
|5||14:25 || Sergei Kamaletdinov "Energetic Electron Outward Radial Transport driven by Drift-Orbit Bifurcation"
|-
|6||14:35 || Alexander Drozdov "Python tools: Rbamlib and MTH5 Electric field data in PySPEDAS"
|-
|7||14:45 || Jay Albert "Resolution of the Greg Cunningham/quasilinear theory issue"
|-
|8||14:55 || Jay Albert "A model of Lauren Blum's periodic microburst observations"
|-
|9||15:05 || FG chairs: closing remarks
|-
|}

== Joint GEM / CEDAR Workshop 2025 ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== 6/24/2024 (Tue) ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== 6/25/2024 (Wed) ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|}

Remaining time for discussion.

=== 6/26/2024 (Thu) ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== 6/27/2024 (Fri) ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Longzhi Gan''', Center for Space Physics, Boston University, lzgan@bu.edu.
*'''Harriet George,''' Institutet för rymdfysik (IRF) / Swedish Institute for Space Physics, harriet.george@irf.se
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu (former chair).

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2026-07-07T13:18:52Z

RB-SoS: /* Schedule */

== GEM workshop 2026 ==

=== Soliciting contributions ===

The RB-SoS focus group is currently soliciting presentations for the 2026 GEM workshop. The RB-SoS focus group is organising five sessions: three stand alone sessions, one joint session with the MPEC focus group, and one joint session with the KiTs, MESO and MAC focus groups.

The topics of these sessions are:
# Stand alone session 1: General contributions related to radiation belt dynamics.
# Stand alone session 2: Cross-population coupling in the inner magnetosphere, e.g. the coupling between the radiation belts and plasmasphere or ring current.
# Stand alone session 3: Event specific dynamics and variability between events, such as evaluating the role of adiabatic vs. non-adiabatic dynamics, radiation belt preconditioning or substorm level during case studies.
# RB-SoS / MPEC joint session: Radiation belt particle precipitation and its drivers, and the ionospheric impacts of this precipitation
# RB-SoS / KiTs / MESO / MAC joint session: Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere, with emphasis on near-Earth reconnection, particle injections, radiation-belt transport, and MI coupling.

To request a presentation in one of these sessions, please fill out this form https://forms.gle/7dBHBybMbr5VwxjV7 by July 6.

The RB-SoS is organising 5 sessions at the 2026 workshop; three stand-alone sessions and two joint sessions.
=== Schedule ===
=== 7/13/2026 (Mon) ===
*1:30 PM - 3 PM: '''RB SoS - topic session''': Event specific dynamics and variability between events [5-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||1:30 || FG chairs: opening remarks
|-
|1||1:37 || Xinlin Li "RB Dynamics from a LEO: New Insights from CIRBE/REPTile-2"
|-
|2||1:44 || Yang Mei "Atmospheric effects controlling Earth's inner radiation belt electrons unveiled by LEO satellite measurements and simulations"
|-
|3||1:51 || Frances Staples "Statistical Characterization of RB Acceleration Timescales Using RBSP and GPS"
|-
|4||1:58 || Lauren Blum "ultra-relativistic electrons in the slot region following geomagnetic storms"
|-
|5||2:05 || David Malaspina "Inferring growth and propagation of whistler-mode waves iusing power spectral density distributions "
|-
|6||2:12 || Huayue Chen "Chorus Element Repetition: Roles of Energetic Electron Injection and Nonlinear Wave Growth"
|-
|7||2:19 || Huayue Chen "Generation of Falling-Tone Whistler-Mode Chorus Waves in the Earth’s Magnetosphere"
|-
|8||2:26 || Greg Riggs "Understanding the Role of ULF Wave Latitude Distribution in Radiation Belt Electron Radial Diffusion"
|-
|9||2:33 || Jinbei Huang "Modeling MP Shadowing using MLT-Resolved Drift Diffusion"
|}
Remaining time for discussion.

== Community resources ==

We are soliciting information on radiation belt products (models, datasets, events) that are useful to the community, in line with the deliverables outlined in our focus group proposal. We aim to collate this information and make it available to the community to facilitate collaboration across the radiation belts community. Examples of products that we aim to collect are datasets / models that can be used to study radiation belt dynamics and contact information of an expert who can be contacted for assistance with that data / model, specific events that you would like to highlight to the community, empirical models related to radiation belt dynamics, etc. If you would like to contribute to this database, please fill out this form: https://docs.google.com/forms/d/e/1FAIpQLSe5OpyJcP-A8Nd6_UNMEw4ZzzjGMov7wpRS0VTeCJEK54GMZA/viewform.

A list of products is available at: https://docs.google.com/spreadsheets/d/1lgc9SX86pXty5XQSFJA-YYt1l_lqT_KnAVfHepixmzY/edit?usp=sharing (navigate the tabs below to see different types).

== VERSIM x GEM Journal Club ==

The RB-SoS focus group is collaborating with VERSIM representatives to organise a journal club, which is held online on the first Wednesday of each month. Our goal is to create a friendly and lively environment where students can learn and engage, and build their scientific confidence. Information on the journal club (including the speaker schedule and zoom information) is available at https://aurora.troja.mff.cuni.cz/versim/index_jc.html.

== Mini-GEM 2025 ==

=== Schedule ===

The RB-SoS focus group will organise one session at the 2025 mini-GEM workshop. This will be held at 13:45 - 15:15 in room 383-385.

{| class="wikitable"
!#!! Time !! Presentations
|-
|1 ||13:45 || Louis Ozeke "A new database of large amplitude EMIC waves detected by the SWARM spacecraft"
|-
|2||13:55 || Xiaofei Shi "Statistical properties of quasi-periodic electron precipitation"
|-
|3||14:05 || Hong Zhao "Ultrarelativistic electron acceleration: Are satellite observations enough to identify the leading mechanism?"
|-
|4||14:15 || Hong Zhao "Bridging the radiation belt and ring current: new insights into energetic particle deep injection"
|-
|5||14:25 || Sergei Kamaletdinov "Energetic Electron Outward Radial Transport driven by Drift-Orbit Bifurcation"
|-
|6||14:35 || Alexander Drozdov "Python tools: Rbamlib and MTH5 Electric field data in PySPEDAS"
|-
|7||14:45 || Jay Albert "Resolution of the Greg Cunningham/quasilinear theory issue"
|-
|8||14:55 || Jay Albert "A model of Lauren Blum's periodic microburst observations"
|-
|9||15:05 || FG chairs: closing remarks
|-
|}

== Joint GEM / CEDAR Workshop 2025 ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== 6/24/2024 (Tue) ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== 6/25/2024 (Wed) ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|}

Remaining time for discussion.

=== 6/26/2024 (Thu) ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== 6/27/2024 (Fri) ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Longzhi Gan''', Center for Space Physics, Boston University, lzgan@bu.edu.
*'''Harriet George,''' Institutet för rymdfysik (IRF) / Swedish Institute for Space Physics, harriet.george@irf.se
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu (former chair).

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2026-07-07T13:09:28Z

RB-SoS:

== GEM workshop 2026 ==

=== Soliciting contributions ===

The RB-SoS focus group is currently soliciting presentations for the 2026 GEM workshop. The RB-SoS focus group is organising five sessions: three stand alone sessions, one joint session with the MPEC focus group, and one joint session with the KiTs, MESO and MAC focus groups.

The topics of these sessions are:
# Stand alone session 1: General contributions related to radiation belt dynamics.
# Stand alone session 2: Cross-population coupling in the inner magnetosphere, e.g. the coupling between the radiation belts and plasmasphere or ring current.
# Stand alone session 3: Event specific dynamics and variability between events, such as evaluating the role of adiabatic vs. non-adiabatic dynamics, radiation belt preconditioning or substorm level during case studies.
# RB-SoS / MPEC joint session: Radiation belt particle precipitation and its drivers, and the ionospheric impacts of this precipitation
# RB-SoS / KiTs / MESO / MAC joint session: Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere, with emphasis on near-Earth reconnection, particle injections, radiation-belt transport, and MI coupling.

To request a presentation in one of these sessions, please fill out this form https://forms.gle/7dBHBybMbr5VwxjV7 by July 6.

The RB-SoS is organising 5 sessions at the 2026 workshop; three stand-alone sessions and two joint sessions.
=== Schedule ===

== Community resources ==

We are soliciting information on radiation belt products (models, datasets, events) that are useful to the community, in line with the deliverables outlined in our focus group proposal. We aim to collate this information and make it available to the community to facilitate collaboration across the radiation belts community. Examples of products that we aim to collect are datasets / models that can be used to study radiation belt dynamics and contact information of an expert who can be contacted for assistance with that data / model, specific events that you would like to highlight to the community, empirical models related to radiation belt dynamics, etc. If you would like to contribute to this database, please fill out this form: https://docs.google.com/forms/d/e/1FAIpQLSe5OpyJcP-A8Nd6_UNMEw4ZzzjGMov7wpRS0VTeCJEK54GMZA/viewform.

A list of products is available at: https://docs.google.com/spreadsheets/d/1lgc9SX86pXty5XQSFJA-YYt1l_lqT_KnAVfHepixmzY/edit?usp=sharing (navigate the tabs below to see different types).

== VERSIM x GEM Journal Club ==

The RB-SoS focus group is collaborating with VERSIM representatives to organise a journal club, which is held online on the first Wednesday of each month. Our goal is to create a friendly and lively environment where students can learn and engage, and build their scientific confidence. Information on the journal club (including the speaker schedule and zoom information) is available at https://aurora.troja.mff.cuni.cz/versim/index_jc.html.

== Mini-GEM 2025 ==

=== Schedule ===

The RB-SoS focus group will organise one session at the 2025 mini-GEM workshop. This will be held at 13:45 - 15:15 in room 383-385.

{| class="wikitable"
!#!! Time !! Presentations
|-
|1 ||13:45 || Louis Ozeke "A new database of large amplitude EMIC waves detected by the SWARM spacecraft"
|-
|2||13:55 || Xiaofei Shi "Statistical properties of quasi-periodic electron precipitation"
|-
|3||14:05 || Hong Zhao "Ultrarelativistic electron acceleration: Are satellite observations enough to identify the leading mechanism?"
|-
|4||14:15 || Hong Zhao "Bridging the radiation belt and ring current: new insights into energetic particle deep injection"
|-
|5||14:25 || Sergei Kamaletdinov "Energetic Electron Outward Radial Transport driven by Drift-Orbit Bifurcation"
|-
|6||14:35 || Alexander Drozdov "Python tools: Rbamlib and MTH5 Electric field data in PySPEDAS"
|-
|7||14:45 || Jay Albert "Resolution of the Greg Cunningham/quasilinear theory issue"
|-
|8||14:55 || Jay Albert "A model of Lauren Blum's periodic microburst observations"
|-
|9||15:05 || FG chairs: closing remarks
|-
|}

== Joint GEM / CEDAR Workshop 2025 ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== 6/24/2024 (Tue) ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== 6/25/2024 (Wed) ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|}

Remaining time for discussion.

=== 6/26/2024 (Thu) ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== 6/27/2024 (Fri) ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Longzhi Gan''', Center for Space Physics, Boston University, lzgan@bu.edu.
*'''Harriet George,''' Institutet för rymdfysik (IRF) / Swedish Institute for Space Physics, harriet.george@irf.se
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu (former chair).

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2026-07-07T13:08:46Z

RB-SoS: /* GEM workshop 2026 */

== GEM workshop 2026 ==

=== Soliciting contributions ===

The RB-SoS focus group is currently soliciting presentations for the 2026 GEM workshop. The RB-SoS focus group is organising five sessions: three stand alone sessions, one joint session with the MPEC focus group, and one joint session with the KiTs, MESO and MAC focus groups.

The topics of these sessions are:
# Stand alone session 1: General contributions related to radiation belt dynamics.
# Stand alone session 2: Cross-population coupling in the inner magnetosphere, e.g. the coupling between the radiation belts and plasmasphere or ring current.
# Stand alone session 3: Event specific dynamics and variability between events, such as evaluating the role of adiabatic vs. non-adiabatic dynamics, radiation belt preconditioning or substorm level during case studies.
# RB-SoS / MPEC joint session: Radiation belt particle precipitation and its drivers, and the ionospheric impacts of this precipitation
# RB-SoS / KiTs / MESO / MAC joint session: Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere, with emphasis on near-Earth reconnection, particle injections, radiation-belt transport, and MI coupling.

To request a presentation in one of these sessions, please fill out this form https://forms.gle/7dBHBybMbr5VwxjV7 by July 6.

The RB-SoS is organising 5 sessions at the 2026 workshop; three stand-alone sessions and two joint sessions.

== Community resources ==

We are soliciting information on radiation belt products (models, datasets, events) that are useful to the community, in line with the deliverables outlined in our focus group proposal. We aim to collate this information and make it available to the community to facilitate collaboration across the radiation belts community. Examples of products that we aim to collect are datasets / models that can be used to study radiation belt dynamics and contact information of an expert who can be contacted for assistance with that data / model, specific events that you would like to highlight to the community, empirical models related to radiation belt dynamics, etc. If you would like to contribute to this database, please fill out this form: https://docs.google.com/forms/d/e/1FAIpQLSe5OpyJcP-A8Nd6_UNMEw4ZzzjGMov7wpRS0VTeCJEK54GMZA/viewform.

A list of products is available at: https://docs.google.com/spreadsheets/d/1lgc9SX86pXty5XQSFJA-YYt1l_lqT_KnAVfHepixmzY/edit?usp=sharing (navigate the tabs below to see different types).

== VERSIM x GEM Journal Club ==

The RB-SoS focus group is collaborating with VERSIM representatives to organise a journal club, which is held online on the first Wednesday of each month. Our goal is to create a friendly and lively environment where students can learn and engage, and build their scientific confidence. Information on the journal club (including the speaker schedule and zoom information) is available at https://aurora.troja.mff.cuni.cz/versim/index_jc.html.

== Mini-GEM 2025 ==

=== Schedule ===

The RB-SoS focus group will organise one session at the 2025 mini-GEM workshop. This will be held at 13:45 - 15:15 in room 383-385.

{| class="wikitable"
!#!! Time !! Presentations
|-
|1 ||13:45 || Louis Ozeke "A new database of large amplitude EMIC waves detected by the SWARM spacecraft"
|-
|2||13:55 || Xiaofei Shi "Statistical properties of quasi-periodic electron precipitation"
|-
|3||14:05 || Hong Zhao "Ultrarelativistic electron acceleration: Are satellite observations enough to identify the leading mechanism?"
|-
|4||14:15 || Hong Zhao "Bridging the radiation belt and ring current: new insights into energetic particle deep injection"
|-
|5||14:25 || Sergei Kamaletdinov "Energetic Electron Outward Radial Transport driven by Drift-Orbit Bifurcation"
|-
|6||14:35 || Alexander Drozdov "Python tools: Rbamlib and MTH5 Electric field data in PySPEDAS"
|-
|7||14:45 || Jay Albert "Resolution of the Greg Cunningham/quasilinear theory issue"
|-
|8||14:55 || Jay Albert "A model of Lauren Blum's periodic microburst observations"
|-
|9||15:05 || FG chairs: closing remarks
|-
|}

== Joint GEM / CEDAR Workshop 2025 ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== 6/24/2024 (Tue) ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== 6/25/2024 (Wed) ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|}

Remaining time for discussion.

=== 6/26/2024 (Thu) ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== 6/27/2024 (Fri) ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Longzhi Gan''', Center for Space Physics, Boston University, lzgan@bu.edu.
*'''Harriet George,''' Institutet för rymdfysik (IRF) / Swedish Institute for Space Physics, harriet.george@irf.se
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu (former chair).

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2026-06-15T15:26:14Z

RB-SoS:

== GEM workshop 2026 ==

=== Soliciting contributions ===

The RB-SoS focus group is currently soliciting presentations for the 2026 GEM workshop. The RB-SoS focus group is organising five sessions: three stand alone sessions, one joint session with the MPEC focus group, and one joint session with the KiTs, MESO and MAC focus groups.

The topics of these sessions are:
# Stand alone session 1: General contributions related to radiation belt dynamics.
# Stand alone session 2: Cross-population coupling in the inner magnetosphere, e.g. the coupling between the radiation belts and plasmasphere or ring current.
# Stand alone session 3: Event specific dynamics and variability between events, such as evaluating the role of adiabatic vs. non-adiabatic dynamics, radiation belt preconditioning or substorm level during case studies.
# RB-SoS / MPEC joint session: Radiation belt particle precipitation and its drivers, and the ionospheric impacts of this precipitation
# RB-SoS / KiTs / MESO / MAC joint session: Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere, with emphasis on near-Earth reconnection, particle injections, radiation-belt transport, and MI coupling.

To request a presentation in one of these sessions, please fill out this form https://forms.gle/7dBHBybMbr5VwxjV7 by July 6.

== Community resources ==

We are soliciting information on radiation belt products (models, datasets, events) that are useful to the community, in line with the deliverables outlined in our focus group proposal. We aim to collate this information and make it available to the community to facilitate collaboration across the radiation belts community. Examples of products that we aim to collect are datasets / models that can be used to study radiation belt dynamics and contact information of an expert who can be contacted for assistance with that data / model, specific events that you would like to highlight to the community, empirical models related to radiation belt dynamics, etc. If you would like to contribute to this database, please fill out this form: https://docs.google.com/forms/d/e/1FAIpQLSe5OpyJcP-A8Nd6_UNMEw4ZzzjGMov7wpRS0VTeCJEK54GMZA/viewform.

A list of products is available at: https://docs.google.com/spreadsheets/d/1lgc9SX86pXty5XQSFJA-YYt1l_lqT_KnAVfHepixmzY/edit?usp=sharing (navigate the tabs below to see different types).

== VERSIM x GEM Journal Club ==

The RB-SoS focus group is collaborating with VERSIM representatives to organise a journal club, which is held online on the first Wednesday of each month. Our goal is to create a friendly and lively environment where students can learn and engage, and build their scientific confidence. Information on the journal club (including the speaker schedule and zoom information) is available at https://aurora.troja.mff.cuni.cz/versim/index_jc.html.

== Mini-GEM 2025 ==

=== Schedule ===

The RB-SoS focus group will organise one session at the 2025 mini-GEM workshop. This will be held at 13:45 - 15:15 in room 383-385.

{| class="wikitable"
!#!! Time !! Presentations
|-
|1 ||13:45 || Louis Ozeke "A new database of large amplitude EMIC waves detected by the SWARM spacecraft"
|-
|2||13:55 || Xiaofei Shi "Statistical properties of quasi-periodic electron precipitation"
|-
|3||14:05 || Hong Zhao "Ultrarelativistic electron acceleration: Are satellite observations enough to identify the leading mechanism?"
|-
|4||14:15 || Hong Zhao "Bridging the radiation belt and ring current: new insights into energetic particle deep injection"
|-
|5||14:25 || Sergei Kamaletdinov "Energetic Electron Outward Radial Transport driven by Drift-Orbit Bifurcation"
|-
|6||14:35 || Alexander Drozdov "Python tools: Rbamlib and MTH5 Electric field data in PySPEDAS"
|-
|7||14:45 || Jay Albert "Resolution of the Greg Cunningham/quasilinear theory issue"
|-
|8||14:55 || Jay Albert "A model of Lauren Blum's periodic microburst observations"
|-
|9||15:05 || FG chairs: closing remarks
|-
|}

== Joint GEM / CEDAR Workshop 2025 ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== 6/24/2024 (Tue) ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== 6/25/2024 (Wed) ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|}

Remaining time for discussion.

=== 6/26/2024 (Thu) ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== 6/27/2024 (Fri) ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Longzhi Gan''', Center for Space Physics, Boston University, lzgan@bu.edu.
*'''Harriet George,''' Institutet för rymdfysik (IRF) / Swedish Institute for Space Physics, harriet.george@irf.se
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu (former chair).

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2026-06-15T15:24:42Z

RB-SoS:

== GEM workshop 2026 ==

=== Soliciting contributions ===

The RB-SoS focus group is currently soliciting presentations for the 2026 GEM workshop. The RB-SoS focus group is organising five sessions: three stand alone sessions, one joint session with the MPEC focus group, and one joint session with the KiTs, MESO and MAC focus groups.

The topics of these sessions are:
1. Stand alone session 1: General contributions related to radiation belt dynamics.
2. Stand alone session 2: Cross-population coupling in the inner magnetosphere, e.g. the coupling between the radiation belts and plasmasphere or ring current.
3. Stand alone session 3: Event specific dynamics and variability between events, such as evaluating the role of adiabatic vs. non-adiabatic dynamics, radiation belt preconditioning or substorm level during case studies.
4. RB-SoS / MPEC joint session: Radiation belt particle precipitation and its drivers, and the ionospheric impacts of this precipitation
5. RB-SoS / KiTs / MESO / MAC joint session: Examination of the Earthward evolution of storm-time magnetotail dynamics and their impacts on the inner magnetosphere, with emphasis on near-Earth reconnection, particle injections, radiation-belt transport, and MI coupling.

To request a presentation in one of these sessions, please fill out this form https://forms.gle/7dBHBybMbr5VwxjV7 by July 6.

== Community resources ==

We are soliciting information on radiation belt products (models, datasets, events) that are useful to the community, in line with the deliverables outlined in our focus group proposal. We aim to collate this information and make it available to the community to facilitate collaboration across the radiation belts community. Examples of products that we aim to collect are datasets / models that can be used to study radiation belt dynamics and contact information of an expert who can be contacted for assistance with that data / model, specific events that you would like to highlight to the community, empirical models related to radiation belt dynamics, etc. If you would like to contribute to this database, please fill out this form: https://docs.google.com/forms/d/e/1FAIpQLSe5OpyJcP-A8Nd6_UNMEw4ZzzjGMov7wpRS0VTeCJEK54GMZA/viewform.

A list of products is available at: https://docs.google.com/spreadsheets/d/1lgc9SX86pXty5XQSFJA-YYt1l_lqT_KnAVfHepixmzY/edit?usp=sharing (navigate the tabs below to see different types).

== VERSIM x GEM Journal Club ==

The RB-SoS focus group is collaborating with VERSIM representatives to organise a journal club, which is held online on the first Wednesday of each month. Our goal is to create a friendly and lively environment where students can learn and engage, and build their scientific confidence. Information on the journal club (including the speaker schedule and zoom information) is available at https://aurora.troja.mff.cuni.cz/versim/index_jc.html.

== Mini-GEM 2025 ==

=== Schedule ===

The RB-SoS focus group will organise one session at the 2025 mini-GEM workshop. This will be held at 13:45 - 15:15 in room 383-385.

{| class="wikitable"
!#!! Time !! Presentations
|-
|1 ||13:45 || Louis Ozeke "A new database of large amplitude EMIC waves detected by the SWARM spacecraft"
|-
|2||13:55 || Xiaofei Shi "Statistical properties of quasi-periodic electron precipitation"
|-
|3||14:05 || Hong Zhao "Ultrarelativistic electron acceleration: Are satellite observations enough to identify the leading mechanism?"
|-
|4||14:15 || Hong Zhao "Bridging the radiation belt and ring current: new insights into energetic particle deep injection"
|-
|5||14:25 || Sergei Kamaletdinov "Energetic Electron Outward Radial Transport driven by Drift-Orbit Bifurcation"
|-
|6||14:35 || Alexander Drozdov "Python tools: Rbamlib and MTH5 Electric field data in PySPEDAS"
|-
|7||14:45 || Jay Albert "Resolution of the Greg Cunningham/quasilinear theory issue"
|-
|8||14:55 || Jay Albert "A model of Lauren Blum's periodic microburst observations"
|-
|9||15:05 || FG chairs: closing remarks
|-
|}

== Joint GEM / CEDAR Workshop 2025 ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== 6/24/2024 (Tue) ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== 6/25/2024 (Wed) ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|}

Remaining time for discussion.

=== 6/26/2024 (Thu) ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== 6/27/2024 (Fri) ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Longzhi Gan''', Center for Space Physics, Boston University, lzgan@bu.edu.
*'''Harriet George,''' Institutet för rymdfysik (IRF) / Swedish Institute for Space Physics, harriet.george@irf.se
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu (former chair).

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2026-01-13T09:29:36Z

RB-SoS:

== Community resources ==

We are soliciting information on radiation belt products (models, datasets, events) that are useful to the community, in line with the deliverables outlined in our focus group proposal. We aim to collate this information and make it available to the community to facilitate collaboration across the radiation belts community. Examples of products that we aim to collect are datasets / models that can be used to study radiation belt dynamics and contact information of an expert who can be contacted for assistance with that data / model, specific events that you would like to highlight to the community, empirical models related to radiation belt dynamics, etc. If you would like to contribute to this database, please fill out this form: https://docs.google.com/forms/d/e/1FAIpQLSe5OpyJcP-A8Nd6_UNMEw4ZzzjGMov7wpRS0VTeCJEK54GMZA/viewform.

A list of products is available at: https://docs.google.com/spreadsheets/d/1lgc9SX86pXty5XQSFJA-YYt1l_lqT_KnAVfHepixmzY/edit?usp=sharing (navigate the tabs below to see different types).

== VERSIM x GEM Journal Club ==

The RB-SoS focus group is collaborating with VERSIM representatives to organise a journal club, which is held online on the first Wednesday of each month. Our goal is to create a friendly and lively environment where students can learn and engage, and build their scientific confidence. Information on the journal club (including the speaker schedule and zoom information) is available at https://aurora.troja.mff.cuni.cz/versim/index_jc.html.

== Mini-GEM 2025 ==

=== Schedule ===

The RB-SoS focus group will organise one session at the 2025 mini-GEM workshop. This will be held at 13:45 - 15:15 in room 383-385.

{| class="wikitable"
!#!! Time !! Presentations
|-
|1 ||13:45 || Louis Ozeke "A new database of large amplitude EMIC waves detected by the SWARM spacecraft"
|-
|2||13:55 || Xiaofei Shi "Statistical properties of quasi-periodic electron precipitation"
|-
|3||14:05 || Hong Zhao "Ultrarelativistic electron acceleration: Are satellite observations enough to identify the leading mechanism?"
|-
|4||14:15 || Hong Zhao "Bridging the radiation belt and ring current: new insights into energetic particle deep injection"
|-
|5||14:25 || Sergei Kamaletdinov "Energetic Electron Outward Radial Transport driven by Drift-Orbit Bifurcation"
|-
|6||14:35 || Alexander Drozdov "Python tools: Rbamlib and MTH5 Electric field data in PySPEDAS"
|-
|7||14:45 || Jay Albert "Resolution of the Greg Cunningham/quasilinear theory issue"
|-
|8||14:55 || Jay Albert "A model of Lauren Blum's periodic microburst observations"
|-
|9||15:05 || FG chairs: closing remarks
|-
|}

== Joint GEM / CEDAR Workshop 2025 ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== 6/24/2024 (Tue) ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== 6/25/2024 (Wed) ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|}

Remaining time for discussion.

=== 6/26/2024 (Thu) ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== 6/27/2024 (Fri) ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Harriet George,''' Institutet för rymdfysik (IRF) / Swedish Institute for Space Physics, harriet.george@irf.se
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu.

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2026-01-13T09:28:14Z

RB-SoS:

== Community resources ==

We are soliciting information on radiation belt products (models, datasets, events) that are useful to the community, in line with the deliverables outlined in our focus group proposal. We aim to collate this information and make it available to the community to facilitate collaboration across the radiation belts community. Examples of products that we aim to collect are datasets / models that can be used to study radiation belt dynamics and contact information of an expert who can be contacted to use that data, case studies that you would like to highlight to the community, empirical models related to radiation belt dynamics, etc. If you would like to contribute to this database, please fill out this form: https://docs.google.com/forms/d/e/1FAIpQLSe5OpyJcP-A8Nd6_UNMEw4ZzzjGMov7wpRS0VTeCJEK54GMZA/viewform.

A list of products is available at: https://docs.google.com/spreadsheets/d/1lgc9SX86pXty5XQSFJA-YYt1l_lqT_KnAVfHepixmzY/edit?usp=sharing (navigate the tabs below to see different types).

== VERSIM x GEM Journal Club ==

The RB-SoS focus group is collaborating with VERSIM representatives to organise a journal club, which is held online on the first Wednesday of each month. Our goal is to create a friendly and lively environment where students can learn and engage, and build their scientific confidence. Information on the journal club (including the speaker schedule and zoom information) is available at https://aurora.troja.mff.cuni.cz/versim/index_jc.html.

== Mini-GEM 2025 ==

=== Schedule ===

The RB-SoS focus group will organise one session at the 2025 mini-GEM workshop. This will be held at 13:45 - 15:15 in room 383-385.

{| class="wikitable"
!#!! Time !! Presentations
|-
|1 ||13:45 || Louis Ozeke "A new database of large amplitude EMIC waves detected by the SWARM spacecraft"
|-
|2||13:55 || Xiaofei Shi "Statistical properties of quasi-periodic electron precipitation"
|-
|3||14:05 || Hong Zhao "Ultrarelativistic electron acceleration: Are satellite observations enough to identify the leading mechanism?"
|-
|4||14:15 || Hong Zhao "Bridging the radiation belt and ring current: new insights into energetic particle deep injection"
|-
|5||14:25 || Sergei Kamaletdinov "Energetic Electron Outward Radial Transport driven by Drift-Orbit Bifurcation"
|-
|6||14:35 || Alexander Drozdov "Python tools: Rbamlib and MTH5 Electric field data in PySPEDAS"
|-
|7||14:45 || Jay Albert "Resolution of the Greg Cunningham/quasilinear theory issue"
|-
|8||14:55 || Jay Albert "A model of Lauren Blum's periodic microburst observations"
|-
|9||15:05 || FG chairs: closing remarks
|-
|}

== Joint GEM / CEDAR Workshop 2025 ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== 6/24/2024 (Tue) ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== 6/25/2024 (Wed) ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|}

Remaining time for discussion.

=== 6/26/2024 (Thu) ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== 6/27/2024 (Fri) ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Harriet George,''' Institutet för rymdfysik (IRF) / Swedish Institute for Space Physics, harriet.george@irf.se
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu.

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2026-01-05T14:03:26Z

RB-SoS:

== VERSIM x GEM Journal Club ==

The RB-SoS focus group is collaborating with VERSIM representatives to organise a journal club, which is held online on the first Wednesday of each month. Our goal is to create a friendly and lively environment where students can learn and engage, and build their scientific confidence. Information on the journal club (including the speaker schedule and zoom information) is available at https://aurora.troja.mff.cuni.cz/versim/index_jc.html.

== Mini-GEM 2025 ==

=== Schedule ===

The RB-SoS focus group will organise one session at the 2025 mini-GEM workshop. This will be held at 13:45 - 15:15 in room 383-385.

{| class="wikitable"
!#!! Time !! Presentations
|-
|1 ||13:45 || Louis Ozeke "A new database of large amplitude EMIC waves detected by the SWARM spacecraft"
|-
|2||13:55 || Xiaofei Shi "Statistical properties of quasi-periodic electron precipitation"
|-
|3||14:05 || Hong Zhao "Ultrarelativistic electron acceleration: Are satellite observations enough to identify the leading mechanism?"
|-
|4||14:15 || Hong Zhao "Bridging the radiation belt and ring current: new insights into energetic particle deep injection"
|-
|5||14:25 || Sergei Kamaletdinov "Energetic Electron Outward Radial Transport driven by Drift-Orbit Bifurcation"
|-
|6||14:35 || Alexander Drozdov "Python tools: Rbamlib and MTH5 Electric field data in PySPEDAS"
|-
|7||14:45 || Jay Albert "Resolution of the Greg Cunningham/quasilinear theory issue"
|-
|8||14:55 || Jay Albert "A model of Lauren Blum's periodic microburst observations"
|-
|9||15:05 || FG chairs: closing remarks
|-
|}

== Joint GEM / CEDAR Workshop 2025 ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== 6/24/2024 (Tue) ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== 6/25/2024 (Wed) ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|}

Remaining time for discussion.

=== 6/26/2024 (Thu) ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== 6/27/2024 (Fri) ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Harriet George,''' Institutet för rymdfysik (IRF) / Swedish Institute for Space Physics, harriet.george@irf.se
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu.

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2025-12-12T08:07:13Z

RB-SoS: /* Schedule */

== '''Mini-GEM 2025''' ==

=== '''Schedule''' ===

The RB-SoS focus group will organise one session at the 2025 mini-GEM workshop. This will be held at 13:45 - 15:15 in room 383-385.

{| class="wikitable"
!#!! Time !! Presentations
|-
|1 ||13:45 || Louis Ozeke "A new database of large amplitude EMIC waves detected by the SWARM spacecraft"
|-
|2||13:55 || Xiaofei Shi "Statistical properties of quasi-periodic electron precipitation"
|-
|3||14:05 || Hong Zhao "Ultrarelativistic electron acceleration: Are satellite observations enough to identify the leading mechanism?"
|-
|4||14:15 || Hong Zhao "Bridging the radiation belt and ring current: new insights into energetic particle deep injection"
|-
|5||14:25 || Sergei Kamaletdinov "Energetic Electron Outward Radial Transport driven by Drift-Orbit Bifurcation"
|-
|6||14:35 || Alexander Drozdov "Python tools: Rbamlib and MTH5 Electric field data in PySPEDAS"
|-
|7||14:45 || Jay Albert "Resolution of the Greg Cunningham/quasilinear theory issue"
|-
|8||14:55 || Jay Albert "A model of Lauren Blum's periodic microburst observations"
|-
|9||15:05 || FG chairs: closing remarks
|-
|}

== Joint GEM / CEDAR Workshop 2025 ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== 6/24/2024 (Tue) ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== 6/25/2024 (Wed) ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|}

Remaining time for discussion.

=== 6/26/2024 (Thu) ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== 6/27/2024 (Fri) ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Harriet George,''' Institutet för rymdfysik (IRF) / Swedish Institute for Space Physics, harriet.george@irf.se
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu.

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2025-11-25T14:18:40Z

RB-SoS:

== '''Mini-GEM 2025''' ==

=== '''Schedule''' ===

The RB-SoS focus group will organise one session at the 2025 mini-GEM workshop. This will be held at 13:45 - 15:15 in room 383-385.

== Joint GEM / CEDAR Workshop 2025 ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== 6/24/2024 (Tue) ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== 6/25/2024 (Wed) ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|}

Remaining time for discussion.

=== 6/26/2024 (Thu) ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== 6/27/2024 (Fri) ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Harriet George,''' Institutet för rymdfysik (IRF) / Swedish Institute for Space Physics, harriet.george@irf.se
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu.

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2025-10-06T09:24:37Z

RB-SoS: /* Chairs */

== '''Joint GEM / CEDAR Workshop 2025''' ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== '''6/24/2024 (Tue)''' ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== '''6/25/2024 (Wed)''' ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|}

Remaining time for discussion.

=== '''6/26/2024 (Thu)''' ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== '''6/27/2024 (Fri)''' ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Harriet George,''' Institutet för rymdfysik (IRF) / Swedish Institute for Space Physics, harriet.george@irf.se
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu.

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2025-06-25T18:27:28Z

RB-SoS: /* 6/25/2024 (Wed) */

== '''Joint GEM / CEDAR Workshop 2025''' ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== '''6/24/2024 (Tue)''' ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== '''6/25/2024 (Wed)''' ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|}

Remaining time for discussion.

=== '''6/26/2024 (Thu)''' ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== '''6/27/2024 (Fri)''' ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Harriet George,''' Laboratory for Atmospheric and Space Physics, CU Boulder, harriet.george@lasp.colorado.edu.
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu.

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2025-06-25T18:25:20Z

RB-SoS: /* 6/25/2024 (Wed) */

== '''Joint GEM / CEDAR Workshop 2025''' ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== '''6/24/2024 (Tue)''' ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== '''6/25/2024 (Wed)''' ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|-
|20||15:10 ||Homayon Aryan

|}

Remaining time for discussion.

=== '''6/26/2024 (Thu)''' ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== '''6/27/2024 (Fri)''' ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Harriet George,''' Laboratory for Atmospheric and Space Physics, CU Boulder, harriet.george@lasp.colorado.edu.
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu.

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2025-06-25T15:08:36Z

RB-SoS: /* 6/25/2024 (Wed) */

== '''Joint GEM / CEDAR Workshop 2025''' ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== '''6/24/2024 (Tue)''' ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== '''6/25/2024 (Wed)''' ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|-
|19||15:05 ||Chirag Skolar
|}

Remaining time for discussion.

=== '''6/26/2024 (Thu)''' ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== '''6/27/2024 (Fri)''' ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Harriet George,''' Laboratory for Atmospheric and Space Physics, CU Boulder, harriet.george@lasp.colorado.edu.
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu.

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2025-06-24T20:18:31Z

RB-SoS: /* 6/25/2024 (Wed) */

== '''Joint GEM / CEDAR Workshop 2025''' ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== '''6/24/2024 (Tue)''' ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== '''6/25/2024 (Wed)''' ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang (presented by Xinlin Li) "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|}

Remaining time for discussion.

=== '''6/26/2024 (Thu)''' ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== '''6/27/2024 (Fri)''' ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Harriet George,''' Laboratory for Atmospheric and Space Physics, CU Boulder, harriet.george@lasp.colorado.edu.
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu.

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2025-06-24T13:59:39Z

RB-SoS: /* 6/24/2024 (Tue) */

== '''Joint GEM / CEDAR Workshop 2025''' ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== '''6/24/2024 (Tue)''' ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes "Energetic Particles: All the Way Down"
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu "Impact of Energetic Particle Precipitation (EPP) on the Upper Atmosphere: Sources and Consequences"
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== '''6/25/2024 (Wed)''' ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|}

Remaining time for discussion.

=== '''6/26/2024 (Thu)''' ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== '''6/27/2024 (Fri)''' ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Harriet George,''' Laboratory for Atmospheric and Space Physics, CU Boulder, harriet.george@lasp.colorado.edu.
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu.

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2025-06-23T13:37:41Z

RB-SoS: /* 6/26/2024 (Thu) */

== '''Joint GEM / CEDAR Workshop 2025''' ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== '''6/24/2024 (Tue)''' ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes TBD
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu TBD
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== '''6/25/2024 (Wed)''' ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|}

Remaining time for discussion.

=== '''6/26/2024 (Thu)''' ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||10:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== '''6/27/2024 (Fri)''' ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Harriet George,''' Laboratory for Atmospheric and Space Physics, CU Boulder, harriet.george@lasp.colorado.edu.
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu.

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2025-06-20T21:04:35Z

RB-SoS: /* 6/25/2024 (Wed) */

== '''Joint GEM / CEDAR Workshop 2025''' ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== '''6/24/2024 (Tue)''' ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes TBD
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu TBD
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== '''6/25/2024 (Wed)''' ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4|| 13:50 || Robert Marshall "LGW model-data comparison"
|-
|5||13:55 ||Zheng Xiang "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|6||14:00 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|7||14:05 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|8||14:10 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|9||14:15 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|10||14:20 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|11||14:25 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|12||14:30 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|13||14:35 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14||14:40 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|15||14:45 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|16||14:50 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|17||14:55 || Drew Turner "Universal radiation belt limits"
|-
|18||15:00 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|}

Remaining time for discussion.

=== '''6/26/2024 (Thu)''' ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||11:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== '''6/27/2024 (Fri)''' ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Harriet George,''' Laboratory for Atmospheric and Space Physics, CU Boulder, harriet.george@lasp.colorado.edu.
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu.

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2025-06-20T01:22:19Z

RB-SoS: /* 6/26/2024 (Thu) */

== '''Joint GEM / CEDAR Workshop 2025''' ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== '''6/24/2024 (Tue)''' ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes TBD
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu TBD
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== '''6/25/2024 (Wed)''' ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4||13:50 ||Zheng Xiang "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|5||13:55 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|6||14:00 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|7||14:05 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|8||14:10 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|9||14:15 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|10||14:20 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|11||14:25 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|12||14:30 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|13||14:35 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|14||14:40 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|15||14:45 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|16||14:50 || Drew Turner "Universal radiation belt limits"
|-
|17||14:55 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|}

Remaining time for discussion.

=== '''6/26/2024 (Thu)''' ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||11:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|}

Remaining time for discussion.

=== '''6/27/2024 (Fri)''' ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Harriet George,''' Laboratory for Atmospheric and Space Physics, CU Boulder, harriet.george@lasp.colorado.edu.
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu.

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2025-06-20T01:21:12Z

RB-SoS: /* 6/24/2024 (Tue) */

== '''Joint GEM / CEDAR Workshop 2025''' ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== '''6/24/2024 (Tue)''' ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||10:00 || FG chairs: opening remarks
|-
|1||10:05 || Allison Jaynes TBD
|-
|2||10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|3||10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|4||10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|5||10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|6||10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|7||10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|8||11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|9||11:09 || Gang Lu TBD
|-
|10||11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11||11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|12||11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== '''6/25/2024 (Wed)''' ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4||13:50 ||Zheng Xiang "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|5||13:55 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|6||14:00 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|7||14:05 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|8||14:10 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|9||14:15 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|10||14:20 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|11||14:25 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|12||14:30 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|13||14:35 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|14||14:40 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|15||14:45 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|16||14:50 || Drew Turner "Universal radiation belt limits"
|-
|17||14:55 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|}

Remaining time for discussion.

=== '''6/26/2024 (Thu)''' ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||11:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|-
| ||11:40 || Discussion
|}

=== '''6/27/2024 (Fri)''' ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Harriet George,''' Laboratory for Atmospheric and Space Physics, CU Boulder, harriet.george@lasp.colorado.edu.
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu.

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2025-06-20T01:19:38Z

RB-SoS: /* 6/25/2024 (Wed) */

== '''Joint GEM / CEDAR Workshop 2025''' ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== '''6/24/2024 (Tue)''' ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
! Time !! Presentations
|-
|10:00 || FG chairs: opening remarks
|-
|10:05 || Allison Jaynes TBD
|-
|10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|11:09 || Gang Lu TBD
|-
|11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== '''6/25/2024 (Wed)''' ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#!! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4||13:50 ||Zheng Xiang "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|5||13:55 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|6||14:00 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|7||14:05 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|8||14:10 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|9||14:15 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|10||14:20 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|11||14:25 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|12||14:30 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|13||14:35 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|14||14:40 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|15||14:45 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|16||14:50 || Drew Turner "Universal radiation belt limits"
|-
|17||14:55 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|}

Remaining time for discussion.

=== '''6/26/2024 (Thu)''' ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||11:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|-
| ||11:40 || Discussion
|}

=== '''6/27/2024 (Fri)''' ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Harriet George,''' Laboratory for Atmospheric and Space Physics, CU Boulder, harriet.george@lasp.colorado.edu.
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu.

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2025-06-20T01:16:45Z

RB-SoS: /* 6/25/2024 (Wed) */

== '''Joint GEM / CEDAR Workshop 2025''' ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== '''6/24/2024 (Tue)''' ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
! Time !! Presentations
|-
|10:00 || FG chairs: opening remarks
|-
|10:05 || Allison Jaynes TBD
|-
|10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|11:09 || Gang Lu TBD
|-
|11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== '''6/25/2024 (Wed)''' ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
!#! Time !! Presentations
|-
| ||13:30 || FG chairs: opening remarks
|-
|1||13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|2||13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|3||13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|4||13:50 ||Zheng Xiang "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|5||13:55 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|6||14:00 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|7||14:05 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|8||14:10 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|9||14:15 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|10||14:20 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|11||14:25 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|12||14:30 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|13||14:35 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|14||14:40 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|15||14:45 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|16||14:50 || Drew Turner "Universal radiation belt limits"
|-
|17||14:55 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|}

Remaining time for discussion.

=== '''6/26/2024 (Thu)''' ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||11:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|-
| ||11:40 || Discussion
|}

=== '''6/27/2024 (Fri)''' ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Harriet George,''' Laboratory for Atmospheric and Space Physics, CU Boulder, harriet.george@lasp.colorado.edu.
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu.

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2025-06-20T01:15:29Z

RB-SoS: /* 6/26/2024 (Thu) */

== '''Joint GEM / CEDAR Workshop 2025''' ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== '''6/24/2024 (Tue)''' ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
! Time !! Presentations
|-
|10:00 || FG chairs: opening remarks
|-
|10:05 || Allison Jaynes TBD
|-
|10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|11:09 || Gang Lu TBD
|-
|11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== '''6/25/2024 (Wed)''' ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
! Time !! Presentations
|-
|13:30 || FG chairs: opening remarks
|-
|13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|13:50 ||Zheng Xiang "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|13:55 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|14:00 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|14:05 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|14:10 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|14:15 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|14:20 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|14:25 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|14:30 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14:35 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|14:40 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|14:45 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|14:50 || Drew Turner "Universal radiation belt limits"
|-
|14:55 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|}

Remaining time for discussion.

=== '''6/26/2024 (Thu)''' ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
!# !! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||11:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|-
| ||11:40 || Discussion
|}

=== '''6/27/2024 (Fri)''' ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Harriet George,''' Laboratory for Atmospheric and Space Physics, CU Boulder, harriet.george@lasp.colorado.edu.
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu.

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2025-06-20T01:15:08Z

RB-SoS: /* 6/26/2024 (Thu) */

== '''Joint GEM / CEDAR Workshop 2025''' ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== '''6/24/2024 (Tue)''' ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
! Time !! Presentations
|-
|10:00 || FG chairs: opening remarks
|-
|10:05 || Allison Jaynes TBD
|-
|10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|11:09 || Gang Lu TBD
|-
|11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== '''6/25/2024 (Wed)''' ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
! Time !! Presentations
|-
|13:30 || FG chairs: opening remarks
|-
|13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|13:50 ||Zheng Xiang "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|13:55 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|14:00 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|14:05 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|14:10 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|14:15 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|14:20 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|14:25 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|14:30 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14:35 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|14:40 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|14:45 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|14:50 || Drew Turner "Universal radiation belt limits"
|-
|14:55 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|}

Remaining time for discussion.

=== '''6/26/2024 (Thu)''' ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
! Time !! Presentations
|-
| ||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||11:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|-
| ||11:40 || Discussion
|}

=== '''6/27/2024 (Fri)''' ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Harriet George,''' Laboratory for Atmospheric and Space Physics, CU Boulder, harriet.george@lasp.colorado.edu.
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu.

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.

FG: Radiation Belts as a System of Systems

2025-06-20T01:14:50Z

RB-SoS: /* 6/26/2024 (Thu) */

== '''Joint GEM / CEDAR Workshop 2025''' ==

The RB-SoS is organising six sessions at the 2025 workshop; three stand-alone sessions and three joint sessions.

=== '''6/24/2024 (Tue)''' ===
*10 AM - 12 PM: '''RB SoS - CEDAR joint session''': Effects of radiation belt particle precipitation on the atmosphere [8-min talks]
{| class="wikitable"
! Time !! Presentations
|-
|10:00 || FG chairs: opening remarks
|-
|10:05 || Allison Jaynes TBD
|-
|10:13 || Mike Shumko "The Loss Through Auroral Microburst Pulsations Satellite (LAMPsat) mission concept"
|-
|10:21 || Joshua Pettit "Can ML replace POES-MEPED for EEP?"
|-
|10:29 || Longzhi Gan "Test Particle Simulations of Dual-Component Microbursts Observed by BARREL: Effects of Atmospheric Back Scattering and Nonlinear Interactions"
|-
|10:37 || Luisa Capannolo "Ionization rates and energy contribution to the atmosphere due to EMIC-driven electron precipitation"
|-
|10:45 || Murong Qin "Influence of Dynamic Magnetospheric Shielding on Solar Energetic Proton Precipitation and the Resultant Atmospheric Ionization"
|-
|10:53 || Lauren Blum "Particle precipitation effects on the atmosphere"
|-
|11:01 || Yang Mei "Analytical Expressions for Atmospheric Elastic Collisional Scattering of Electrons in Magnetic Fields"
|-
|11:09 || Gang Lu TBD
|-
|11:17 || Katrina Bossert "Using AIRS and SABER CO2 NLTE emissions as tracers for gravity wave and polar vortex interactions with energetic particles"
|-
|11:25 || Hanli Liu "It's YES for NO: Transport of Nitric Oxide in the winter MLT region"
|-
|11:33 || Lynn Harvey "A review of Sun-Earth coupling via the descent of EPP-produced NOx"
|}
Remaining time for discussion.

*13:30 PM - 15:30 PM: '''RB SoS - CP joint session''': Coupling between the plasmasphere and the radiation belts
**''Please refer to the CP Focus Group''

=== '''6/25/2024 (Wed)''' ===
*10 AM - 12 PM: '''RB SoS session: round-table discussion'''

*13:30 PM - 15:30 PM: '''RB SoS session: general contributions''' [lightning talks: 5-min talks, 3 slides]
{| class="wikitable"
! Time !! Presentations
|-
|13:30 || FG chairs: opening remarks
|-
|13:35 ||Xinlin Li "Myth vs. Measurement: Relativistic Electrons and Energetic Protons in the Inner Belt"
|-
|13:40 ||Lauren Blum "Results on MeV electron lifetimes in the inner belt (and lightning-driven precipitation)"
|-
|13:45 ||Alexander Shane "Lightning-Generated Whistlers: Variability of Event-Specific Wave Distributions"
|-
|13:50 ||Zheng Xiang "Fine Structure of Relativistic Electron Precipitation Driven by EMIC Waves: CIRBE/REPTile-2 Measurements and Their Physical Implications"
|-
|13:55 ||Zhi Gu (Patrick) Li "Including Atmospheric Backscatter Effects in Modeling of EMIC Wave-Driven Precipitation"
|-
|14:00 ||Homayon Aryan "Enhanced Radiation Exposure of Airline Crew and Passengers"
|-
|14:05 ||Sungjun Noh "A Machine Learning-Based Probabilistic Model for Global EMIC Wave Activity Using Van Allen Probes Observations"
|-
|14:10 ||Jinbei Huang "Modeling the Outer Radiation Belt Electron Loss using a New MLT-Resolved Drift-Diffusion Model"
|-
|14:15 ||Jiabei He "Statistical Study of Chorus Element Repetition Time from Van Allen Probes"
|-
|14:20 ||Zhiyang Xia "Spatial Scale Analysis of Rising Tone Chorus Elements"
|-
|14:25 ||Mirek Hanzelka "Ultrarelativistic electron acceleration disrupted by the 3D spatial structure of chorus"
|-
|14:30 ||Evan McPherson "Imbalanced Regressive Model of Electron Fluxes in the Earth's Outer Radiation Belt"
|-
|14:35 ||Man Hua "Radiation belt electron acceleration inside the plasmasphere"
|-
|14:40 ||Yi-Ting Chen "Machine Learning Techniques to Reveal the Relationship Between Solar Wind and Electron Precipitation"
|-
|14:45 ||Ryan Dewey "An electron radiation belt at Mercury"
|-
|14:50 || Drew Turner "Universal radiation belt limits"
|-
|14:55 ||Jay Albert "New estimate of the flux both outside and inside the loss cone due to pitch angle diffusion"
|}

Remaining time for discussion.

=== '''6/26/2024 (Thu)''' ===
*10 AM - 12 PM: '''RB SoS topic session''': Magnetotail impacts on the radiation belts [15-min talks]
{| class="wikitable"
! Time !! Presentations
|-
|-||10:00 || FG opening remarks
|-
|1||10:05 ||Man Hua "Estimating Storm-Time Maximum Fluxes of Outer Radiation Belt Electrons: Combining Van Allen Probes and GPS Satellite Observations"
|-
|2||10:20 ||Louis Ozeke "How Relativistic Electron Injections from the Magnetotail can cause Multi-MeV Flux Enhancements in the Outer Radiation Belt"
|-
|3||10:35 ||Rui Chen "Observational Evidence for the Nonlinear Growth of Chorus Waves Caused by Substorm Injected Energetic Electrons"
|-
|4||11:50 || Mike Shumko "What is the relationship between the aurora and relativistic electron precipitation during a storm-time substorm"
|-
|5||11:05 ||Kareem Sorathia "Direct Radiation Belt Injections and their Auroral Counterparts"
|-
|6||11:20 ||Larry Lyons "Connection Between Magnetotail Flow Burst and Radiation Belt Injections as Revealed by Auroral Streamers and Ground Magnetometers"
|-
|7||11:35 ||Xiangning Chu "Machine Learning-Based Reconstruction of Radiation Belt Parameters During New GEM ML Challenge Storms" (5 min)
|-
|-||11:40 || Discussions
|}

=== '''6/27/2024 (Fri)''' ===
*10 AM - 12 PM: '''RB SoS - COMP joint session''': Radiation belts of other planets
**''Please refer to the COMP Focus Group''

== Full FG Proposal ==

=== Title ===

Radiation Belts as a System of Systems (RB-SoS)

=== Chairs ===

*'''Harriet George,''' Laboratory for Atmospheric and Space Physics, CU Boulder, harriet.george@lasp.colorado.edu.
*'''Man Hua,''' Department of Atmospheric and Oceanic Sciences, UCLA, manhua@ucla.edu.
*'''Adam Michael,''' Johns Hopkins Applied Physics Laboratory, adam.michael@jhuapl.edu.
*'''Luisa Capannolo,''' Center for Space Physics, Boston University, luisacap@bu.edu.

=== Research Area ===

Inner MAGnetosphere (IMAG)

=== Term Length ===

2025 - 2029

=== Abstract ===

The Earth’s radiation belts are highly variable in terms of both particle dynamics and wave activities, and are a key component of the magnetospheric energy flow. This energy flow is initiated in the solar wind, is transmitted through magnetotail reconnection and enters the radiation belts through processes such as advection or injections, and this energy can then be deposited into the atmosphere to generate aurora and affect atmospheric chemistry. This results in a strong coupling of the radiation belts to multiple other systems. A physically consistent understanding of the radiation belts that includes coupling to these other systems within the global magnetosphere is therefore required to accurately model the radiation belts.

The overarching goal of this focus group (FG) is to '''evaluate the complex variability of Earth’s radiation belts as part of the heliospheric ‘system-of-systems’''', determining how the radiation belts affect and are affected by different coupled systems. This FG considers the inner and outer belts, the slot region, and temporary ‘third belt’, the particles (protons, electrons and heavy ion species) populating these belts, and the inner magnetospheric plasma waves that interact with radiation belt particles.
This focus group will evaluate how radiation belt particle dynamics, inner magnetospheric plasma waves, wave-particle interactions and system-wide dynamics couple to the following regions:
*A. Solar wind and interplanetary magnetic field (IMF)
*B. Magnetotail
*C. Ionosphere and atmosphere
*D. Other inner magnetospheric plasma populations, such as the ring current and plasmasphere

=== Topic Description ===

The science goals that this FG will focus on, with emphasis on coupling to systems A – D, are:
# '''Determine and quantify how radiation belt particle dynamics are controlled by and how they affect systems that couple to the terrestrial radiation belts.''' This includes phenomena such as the rates of acceleration, transport or loss under different solar wind, geomagnetic storm and substorm conditions, radiation belt precipitation as an input to the atmosphere/ionosphere system, and radiation belt particle dynamics following particle injections from the magnetotail. This inherently includes evaluation of the impact of wave-particle interactions that are modulated by the coupled systems, which are elaborated on in Goal 2.
# '''Determine how plasma wave activity within the inner magnetosphere is governed by the coupled systems, and quantify the importance of wave activity to particle dynamics via wave-particle interactions.''' This includes evaluating the role that coupled systems play on the spatial distribution (including magnetic local time distribution), growth rate and intensity of inner magnetospheric plasma waves. For example, magnetotail injections create particle anisotropies that can lead to plasma wave generation. The plasmapause also acts as a boundary between the growth of whistler-mode chorus and hiss waves. The coupled systems, therefore, play a defining role in the generation and characteristics of inner mag- netospheric waves. Radiation belt wave-particle interactions are further modulated by these coupled systems. The distribution of cold plasma can alter both the efficiency of wave-particle interactions and the spatial extent of the region where the interaction takes place, impacting the particle dynamics that are considered in Goal 1, such as the rates of pitch-angle scattering or acceleration.
# '''Evaluate how system-wide radiation belt evolution is modulated by the coupled systems, and the effect that these system-wide dynamics have on the coupled systems.''' This goal specifically evaluates radiation belt dynamics that persist significantly longer than a drift period (≳ hours/days) and affect the entire radiation belt environment, such as long-term dropouts and enhancements. For example, some geomagnetic storms and substorms drive radiation belt enhancements more efficiently than other storms, so determining the solar wind and/or magnetotail conditions that result in this varying enhancement efficiency is an important aspect of accurate geospace modeling that is encompassed by this FG. This science topic includes determining and quantifying the effects that large-scale radiation belt dynamics have on the coupled systems, such as the impact of particle precipitation during radiation belt dropout events on the atmosphere/ionosphere system.

Evaluation of the influence of the solar wind on the Earth’s radiation belt includes the impact that specific solar wind/IMF parameters have on the radiation belts. The FG additionally includes evaluation of the impact of solar wind transients, such as high speed solar wind streams or coronal mass ejections, on long-term, system-wide radiation belt enhancements or dropouts, and variations in the radiation belts on solar-cycle timescales that result from changing solar wind/IMF conditions throughout the solar cycle.

The coupling of the magnetotail to the radiation belts includes evaluation of the impact of geomagnetic storms and substorm activity on the radiation belts, as well as transient phenomena such as bursty bulk flows or dipolarization fronts. This FG additionally encompasses studies evaluating the magnetotail as a source of radiation belt particles, such as the evaluation of how often and in which conditions the plasma sheet acts as a source of energetic radiation belt particles, and the effect of these particle injections on inner magnetospheric wave generation and the subsequent wave-particle interactions.

The Earth’s inner magnetosphere is composed of a range of plasma population, such as the ring current and plasmasphere, that interact with the radiation belts. For example, different wave modes arise inside and outside the plasmasphere, so the plasmapause plays a key role in defining the spatial extent and key characteristics of inner magnetospheric waves that interact with radiation belt particles, while the ring current results in phenomena such as the Dst effect.

Determining the coupling of the atmosphere/ionosphere system on the radiation belt includes both the effects of the radiation belts on the atmosphere/ionosphere and the effects that the atmosphere/ionosphere have on the radiation belt environment. Radiation belt particle precipitation deposits mass and energy into the atmosphere/ionosphere, which can have significant space weather and climatological impacts. This FG therefore encompasses studies related to the pitch-angle scattering of radiation belt particles that results in precipitation, which can occur through a range of interactions (including non-linear interactions) with inner magnetospheric waves. Ionospheric outflow is also a source of inner magnetospheric particles, and multiple current systems couple the inner magnetosphere and ionosphere; evaluation of the impacts of these phenomena, and other ionospheric or atmospheric dynamics, on the radiation belts are in-scope for this FG.

=== Timeliness ===

The timeliness of this FG is underscored by:
# '''Unprecedented observational datasets:''' Recent and ongoing missions, such as the Van Allen Probes, Arase, THEMIS, MMS, DSX, an increasing number of current and upcoming CubeSat missions (e.g., ELFIN, CIRBE, FIREBIRD, REAL, AEPEX, CANVAS, GTOSat), and balloons (e.g., BARREL), coupled with long-term data from NOAA/GOES, POES, LANL/GEO, and GPS, provide a unique opportunity for a comprehensive investigation of radiation belt wave and particle dynamics.
# '''Recent intense space weather events:''' Radiation belt dynamics drastically varied during the most intense space weather events in the last 20 years (e.g., the Gannon storm in May 2024 with Dst below -400 nT). The datasets mentioned above cover multiple stages of the solar cycle, allowing for the exploration of whether existing knowledge of radiation belts during solar minimum can be extended to solar maximum, which has both significant scientific and practical interests.
# '''New insights into system interactions:''' Significant advances have been made in understanding the impact of other systems, such as the solar wind and IMF, substorm injections from the magnetotail, and plasma populations from the ring current and plasmasphere on radiation belt dynamics, which in turn, affect the relevant physical processes in their coupling systems (e.g., ionosphere/atmosphere). Therefore, investigating the radiation belts within this system-wide framework is a fundamental and open science question that brings together the community to foster a deeper understanding of radiation belts, and their role within the solar system as a whole.
# '''Advancements in modeling:''' Newly developed cross-scale, self-consistent models, combining the global MHD simulations with simulations of local wave-particle interactions (e.g., MAGE, K2), drift- resolved diffusion models, models including nonlinear effects, and novel machine-learning models, offer new capabilities for simulating radiation belt particle dynamics. These models also enhance our understanding of the correlation of the different domains of the geospace, and the relative importance of different driving factors on the radiation belt dynamics. There is a critical need to explore how radiation belt particles serve as inputs and outputs in these broader geospace processes.
# '''Continued community interest:''' Radiation belt physics is a strong interest within the GEM community. The recently concluded FG, “System Understanding of Radiation Belt Particle Dynamics through Multi-spacecraft and Ground-based Observations and Modeling” (2019–2024), was highly successful in terms of participation, scientific output, and impact. Our proposed FG will build on these achievements by advancing investigations into radiation belt physics, while also emphasizing a holistic understanding of the radiation belts as part of the heliospheric “system-of-systems”, focusing on both their impacts on and interactions with other systems.

=== Relevance to Existing FGs ===

This proposed FG will actively collaborate with the following ongoing GEM FGs to achieve a system level understanding of the radiation belt dynamics:
# '''Mesoscale drivers of the nightside transition region: ionospheric and magnetotail evaluations (2022 – 2026):''' Particle dynamics in the magnetotail can have significant impacts on radiation belt dynamics. Investigating the energization of particles within the nightside transition region will provide valuable insights into radiation belt particle acceleration processes.
# '''Magnetospheric Sources of Particle Precipitation and Their Role on Electrodynamic Coupling of Magnetosphere-Ionosphere-Thermosphere Systems (2022 – 2026):''' Particle precipitation to the upper atmosphere is a major loss mechanism for the radiation belt particles, which plays an important role in determining and modeling ionospheric electrodynamics. The proposed FG intends to coordinate joint sessions to investigate the contribution of the radiation belt particle precipitation to the electrodynamics of the M-I-T system.
# '''The Impact of the Cold Plasma in Magnetospheric Physics (2020 – 2025):''' The cold plasma plays a crucial role in controlling waves and wave-particle interactions, which are fundamental to the radiation belt particle dynamics. Collaborative efforts between this FG and the proposed one will enhance understanding of how cold plasma modulates radiation belt processes.
# '''Kinetic Plasma Processes in the Magnetotail during Substorm Dynamics (2024 – 2028):''' This FG focuses on understanding the plasma populations, thin current sheets, and particle energization in the magnetotail region, which provide an important source of particles that will feed into the inner magnetosphere. Joint efforts with the proposed FG will provide invaluable insight about the chain of physical processes from the energized particles during substorm onset in the magnetotail region to the radiation belt electron dynamics.
# '''Self-Consistent Inner Magnetospheric Modeling (2020 – 2025):''' This FG focuses on the under- standing and modeling the wave growth driven by ring current particles and wave-particle interactions across different populations. Joint efforts with the proposed FG, which emphasizes radiation belt particles, are essential for a comprehensive understanding of the dynamics of Earth’s inner magnetosphere.
# '''Comparative Planetary Magnetospheric Processes (2023 – 2027):''' A key topic of this FG is the comparative study of radiation belt physics across drastically different planetary magnetospheres. The proposed FG plans to coordinate joint sessions to explore comparative radiation belt wave and particle dynamics, and their role as input/output to other environments (solar wind and interplanetary magnetic field, magnetotail region, atmosphere/ionosphere, etc.) to unravel missing or poorly understood physical processes.

=== Goals and Deliverables ===

During the four years of the RB-SoS FG, we will encourage research focused on the key topics and guide the community to investigate these topics in relation to the identified coupled systems (solar wind, magnetotail, ionosphere/atmosphere, and other inner magnetospheric plasma populations). Additionally, we will strive to produce the following deliverables to make radiation belt research more easily accessible to the community. Repositories of events and models are currently limited, and we will collect data analysis and modeling results to facilitate and encourage collaboration across researchers from the radiation belt community and others as well. We envision such repositories as spreadsheets listing information relevant to the data/model, any existing documentation (e.g., readme files, papers), list of contributing researchers and respective emails, and links to the data/models. The repositories and collections will be updated periodically after each GEM or mini-GEM meeting and their URLs will be available in the GEM Wiki.
# ''' Repository of statistical data analysis''' useful to the community (i.e., maps of wave amplitudes, precipitation, wave growth rates, storm/substorm lists, enhancement/dropout RB events, diffusion coefficients, etc.). These are available in published papers, however, not all papers provide public access to the statistical results. We will strive to make the existing statistical analysis available to the community to facilitate follow-up studies, in particular for CubeSat studies which often entail more data analysis challenges.
# '''Collection of papers''' focused on investigating the radiation belts as a system-of-systems and published during the RB-SoS FG term. We will also write a white paper at the end of the FG term highlighting our progress, identifying the system coupling with largest uncertainties, and describing possibly new research avenues to explore.
# ''' Collection of events''' analyzed through data analysis and modeling. We will flag events as “complete” (i.e., understood) or as “incomplete” (i.e., further research is needed). Particularly interesting events will also be highlighted to encourage investigation by the community.
# '''Repository of new techniques and models ''' particularly suitable from a perspective of systems-of- systems (i.e., empirical, coupled, AI-based, etc.). We will strive to collect existing models applicable to radiation belt physics.

=== Expected Activities ===

In an effort to align with the “GEM-Style”, we will structure our sessions to encourage more interaction and discussion while encouraging participation from early career researchers and those in underrepresented groups. In line with the community’s needs and interests at the time of each meeting, individual sessions styles will be selected from one of the following formats:
# '''Round Table Discussions:''' Current open questions will be posed to the community prior to the start of the workshop. Building upon current and previous focus groups, the session will be separated into two equal parts. The session will begin with discussions amongst smaller groups to promote meaningful dialog among more participants and to avoid the conversation being dominated by a few individuals. The second portion will consist of an open conversation with the entire room to compile and share ideas. The discussions will be moderated by the FG leads and selected experts on the topic.
# ''' Work in Progress:''' We will solicit presentations with an emphasis on ongoing research. Any study related to one of our science goals is permissible. This will enable discussion with the community, providing feedback to the presenter prior to completion of individual projects and will provide those who would like to present their work on any relevant topic with an opportunity to do so.
# '''Targeted Topics: '''In sessions selected to examine specific topics of interest, we will solicit presentations on one aspect related to our science goals. These sessions will have one of two formats: 1) a panel discussion, or 2) two scene setting talks followed by short presentations, solicited from the community, that continue the discussion started by the scene-setters. Again, the discussions will be moderated by the FG leads and selected experts on the topic.
# '''Event-based Sessions:''' We will reserve specific sessions to investigate the radiation belt dynamics during events of particular interest to the community, such as the May 2024 superstorm. These sessions will help facilitate the collection of events and the related data analysis/modeling efforts described in our goals and deliverables.
# '''Joint sessions:''' Due to the interconnection between the radiation belts and other regions within geospace, joint sessions with other focus groups will be key to promote discussion amongst the com- munity. As described above, these sessions will focus on fundamental processes that drive radiation belt dynamics and detail how the radiation belts coevolve and impact other systems within geospace.