FG: Comparative Planetary Magnetospheric Processes

2023 GEM Summer Workshop
COmparative Planetary Magnetospheric Processes (COMP) focus group will hold 2 stand-alone sessions and 2 joint sessions.

COMP Session 1 (10:30–12:00 Monday, June 12, Rm A)
Exploring the parameter space of magnetospheric physics
10:30   Overview of FG
10:40   Scene Setting Talk: magnetospheric dynamics and reconnection (Dan Gershman)
10:55   Grant Stephens: magnetic field modeling of Mercury, Earth, & Saturn
11:05   Ryan Dewey: Mercury's dawn-dusk magnetotail asymmetries and their relationship with magnetic activity
11:15   Xuanye Ma: Review of the KHI at the different planets

Open discussion: what are the big questions that can be addressed by exploring the vast physical parameter space within our solar system? (Co-chairs, Fran Bagenal, Bob Lysak)
11:25   Some elements to consider: Modeling capabilities; maturity of topic & data sets; relevance to comparative planetary needs/topics
11:55   Summary and future endeavors

COMP Session 2: MPEC-COMP Joint Session (10:30–12:00 Tuesday, June 13, Rm A)
10:30   Opening remarks
10:40   Bob Lysak: MI-coupling w/ emphasis on comparative processes between Earth & Jupiter
10:55   Jim Raines: Cusp precipitation at Mercury

COMP Session 3 (13:30–15:00 Tuesday, June 13, Rm Coa)
13:30   Summary & refined open questions from previous sessions
13:45   Lisa Winter: NSF talk on comparative planetary magnetosphere funding opportunities
13:55   Nithin Sivadas: Solar wind driving of planetary magnetospheres
14:05   Chuanfei Dong: Using Mercury and Ganymede to Learn Earth’s Responses to Extreme Space Weather Events
14:15   Jaya Joseph: ECH waves at Jupiter and some comparisons with Earth and Saturn
14:25–15:30   Open discussion on various topics (panel members: Co-chairs, Fran Bagenal, Bob Lysak)

• Ideas on how to best organize topics/goals to address the big questions
• Identify specific case events in various mission data sets & potential GEM challenges that will help enable the community to address the open questions
• Coordinating efforts and discussion of potential funding avenues for cross-divisional/disciplinary science

COMP Session 4: COMP-RB-DIP Joint Session (10:30–12:00 Wednesday, June 14, Rm A)
10:30   Opening remarks from FG leads
10:40   Scene Setting Talk: Radiation belt dynamics w/ emphasis on comparative source and acceleration processes (Peter Kollmann)
10:55   Sasha Drozdov: Modeling of Saturn’s radiation environment using the VERB code
11:05   Anthony Sciola: Comparing injections and interchange instability between Earth and Saturn
11:15   Anton Artemyev: Role of electron field-aligned streams in current sheet configuration in Jovian and Earth magnetotails
11:15–12:00   Open Discussion + Walk-in talks

Chairs

Focus Group Chairs

Name	Affiliation	Contact Details
George Clark	John Hopkins Applied Physics Lab	george.clark at jhuapl.edu
Wen Li	Boston University	wenli77 at bu.edu
Bob Marshall	University of Colorado Boulder	robert.marshall at colorado.edu
Dan Gershman	NASA Goddard Space Flight Center	daniel.j.gershman at nasa.gov
Peter Delamere	University of Alaska Fairbanks	padelamere at alaska.edu
Shannon Curry	University of California, Berkeley	smcurry at berkeley.edu

Science Topic

The Solar System is gifted with a diverse array of magnetospheric systems, from the familiar Dungey-cycle-driven system at Earth, to the extreme Vasyliunas-cycle-driven Gas Giants, to the unmagnetized-solar wind interactions found at Mars and Venus. Together, this diverse set of planetary magnetospheres makes it possible to probe fundamental physical processes by exploring how and under what conditions they operate in and across the Solar System. Furthermore, if we can make sense of this large parameter regime then not only will we improve our understanding of the geospace environment, but we may be able to close the gap in our understanding of plasma physics elsewhere in the cosmos, e.g., magnetospheres of pulsars and brown dwarfs. However, to reach that goal, it requires the Earth and Planetary space physics communities to give serious consideration to the physics behind the similarities and differences between these systems. That brings us to the primary goal of this focus group (FG)—to assess the physical processes within our Solar System that ultimately shape these planetary magnetospheric environments with the aim of uncovering parameter regimes associated with distinct and universal mechanisms.

Studying all the processes is an overwhelming and unrealistic task, so we propose the following key comparative topics that directly relate to the active GEM focus groups: 1) comparative magnetotail dynamics and their effects on the transport of mass, momentum, energy, and magnetic flux; 2) comparative planetary radiation belts and ring currents and the processes that source and sustain them across drastically different magnetospheres; 3) comparative magnetosphere-ionosphere coupling mechanisms, e.g., precipitation, acceleration, outflow, and drivers across solar wind driven, internally driven, and induced magnetospheres. Even still this list is quite broad relative to the typical GEM FGs; however, one of the main objectives of this FG is to establish GEM as the leading forum where comparative planetary magnetospheric processes are workshopped to foster interactions between communities. In a way, this is similar to the original NSF initiative that led to the GEM program where we are aiming to form a community consensus on the outstanding questions that can be addressed on a few year time scale. Therefore, our expectation is that after we establish the big open questions that are common across planetary magnetospheres, we can then workshop those by making novel use of the datasets and modelling outputs available.

Goals & Deliverables

• Primary Community Goal: Establish GEM as the leading forum where comparative planetary magnetospheric processes are workshopped to foster interactions between communities.
• Primary Science Goal: Assess the physical processes within our Solar System that ultimately shape the diverse planetary magnetospheric environments with the aim of uncovering

parameter regimes associated with distinct and universal mechanisms.
Community Deliverables: 1) First and foremost, develop a forum where the GEM and planetary magnetospheric (a relatively small group) communities can come together to discuss the most interesting and pressing synergistic problems; 2) develop tools and user guides (including a compendium of relevant papers) to facilitate in sharing of data and simulation outputs between the Earth and Planetary magnetospheric communities; 3) produce an event list across the various Planetary and Terrestrial missions for the community to focus on specific comparative aspects.
Science Deliverables: 1) evaluate the maturity of specific magnetospheric processes at different planets (e.g., importance of radial transport in supplying radiation belts, how material laden magnetospheres sculpt particle distributions, how ion outflow is modified between strongly and Figure 2: Images of Jupiter’s (panel A), and Earth’s (panel B) northern auroral regions. Right panel illustrates Jupiter’s modeled magnetic field based on its fast rotation and interaction with the solar wind. Credit: Zhang et al. (2021). weakly magnetized planets, etc.) and the robustness of corresponding datasets; 2) once objective 1 is complete, rank specific outstanding problems that can be addressed within current observations and modelling capabilities; 3) strive to develop semi-empirical relationships associated with the outstanding problems in objective (2) to aid in future modelling efforts.