*************************** ** THE GEM MESSENGER ** *************************** Volume 20, Number 27 October 3, 2010 ---------------------------------------------------------------------- 1. 2010 Summer Workshop Report: Inner Magnetosphere-Storms Research Area ---------------------------------------------------------------------- From: Reiner Friedel, LANL Anthony Chan, Rice University This year's GEM workshop was an active one for the Inner-Magnetosphere Storms Research Area. In particular with the new of the new Radiation Belts and Wave Modeling Focus Group. This is a highly topical FG in light of the upcoming RBSP Mission, which hosted specific sessions on modeling in support of the RBSP science objective. At times close to half of all GEM attendees crowded into the Sessions of this Focus Group, and larger rooms needed to be sought! RBSP related themes were prevalent in most of the focus groups, with several joint session highlighting the required linking up of traditionally separate research regimes if progress is to be made. The Space Radiation Climatology FG entered it's final year and plans were laid for its wrap up at this GEM. What follows here are the individual Reports on the GEM SUMMER activities on the IMS and joint Focus Groups. *** IMS FG on Plasmasphere-Magnetosphere Interactions (PMI) Conveners: J. Goldstein, M. Spasojevic, J. Borovsky This is a report of activities of the Plasmasphere-Magnetosphere Interactions (PMI) Focus Group (FG) at the 2010 Geospace Environment Modeling (GEM) Workshop in Snowmass, Colorado. This document presents a broad overview of the physical ideas discussed rather than a detailed summary of each and every presentation. Documents posted on the PMI Wiki Page http://tinyurl.com/pmiFGwiki This report and detailed information about the presentations is available on the PMI Wiki Page, as follows. PMI10_Session_Notes.doc Detailed notes from the various PMI sessions. GEM_PMI10_v4.pdf The schedule of presentations for all PMI sessions. Format of the 2010 GEM PMI Sessions Presenters were encouraged (both in advance and at the sessions) to keep their presentations brief and informal, leaving time for questions and discussions, fostering an atmosphere of active exchange of ideas among speaker and audience. PMI Breakout Sessions To address the PMI FG's central question, "How Are Magnetospheric Processes Regulated By Plasmaspheric Dynamics (and Vice Versa)?" we hosted five (5) Breakout sessions at the 2010 GEM Summer Workshop. PMI Breakout 5 was convened jointly with the Radiation Belts & Wave Modeling (RBWM) focus group. The detailed schedule (GEM_PMI10_v4.pdf) is posted on the PMI Wiki. These PMI Breakout sessions were very well-attended, and there was generally a great deal of animated discussion. It was resolved that at GEM 2011 to more actively discourage any formal presentations. In this next section of the PMI Focus Group Report, each PMI Breakout Session is listed with its Topic, and Purpose, followed by a brief summary of what was discussed and accomplished at the session. This report is a top-level report. If you are looking for detailed notes on individual PMI talks, please see PMI10_Session_Notes.doc, posted on the PMI Wiki page. Monday, 21 June 2010 PMI Breakout 1: 10:30am - 12:15pm. Topic: "EMIC Waves". This session featured four (4) presentations by Denton, Posch, MacDonald, and Fraser. EMIC linear wave growth proxies are in agreement with actual EMIC wave observations, and can be useful where actual wave measurements are not available. Simulations indicate that knowledge of cold plasma composition is crucial to properly constrain and understand EMIC wave propagation and growth. While cold plasma properties make a big difference in simulations of EMIC wave growth and propagation, statistical analysis of ground-based Pc1 observations from AGO stations reveals at best a weak correlation with the simultaneous occurrence at geostationary orbit of plasmaspheric plumes. On the other hand, EMIC wave occurrence does correlate well with solar wind pressure pulses. It has been noted before that EMIC waves can be produced by magnetospheric compression or temperature anisotropy in a ring-current/plume overlap region. In CRRES observations, EMIC waves are much more likely to occur during main phase, and found to occur in the plasmaspheric "drainage corridor", i.e., the noon-to-dusk MLT sector, at L-values nominally occupied by the ring current. Taken together, these observations might indicate the need to separate out EMIC wave events into those triggered by pressure pulses and those possibly growing in the plume. PMI Breakout 2: 1:30 - 3:00pm. Topic: "Wave-Particle Interactions". Five (5) presentations were given in this session, by Streltsov, Chen, Jordanova, Clausen, and Albert. Simulations were prominent in this session, providing some key results. Ducting of whistlers is most effective for density irregularities satisfying particular relationships to the wave properties. Modeling of mgnetosonic wave growth in the nonlinear approximation reveals that the unstable frequency band is modulated by the non-Maxwellian ("ring") velocity of the hot ions normalized to the bulk Alfven speed. Non-linear (or quasi-linear) theory may very well be required, in fact, given some very large wave amplitudes (e.g., 2-100 mV/m chorus) found in recent observations. Ring current ion pitch-angle anisotropy has a peak near dusk when self-consistent magnetic fields are included, and there is also a peak in EMIC wave growth in this local time sector, consistent with CRRES statistical studies of Breakout 1 (see above). Penetration electric fields have a strong influence on the lower-energy range of the ring current, and these fields are observed in SuperDARN radar to closely correlate with the IMF north-south conponent, with a 15-20 minute delay—consistent with recent IMAGE-EUV-based estimates for the "penetration delay time" for the inner magnetospheric E-field. PMI Breakout 3: 3:30 - 5:00pm. Topic: "Plasmaspheric Dynamics and Plume Recirculation". This session hosted six (6) presentations, by Chappell, Liemohn, Gallagher, Schulz, Ozhogin, and Tu. The concept of a "plasmaspheric drainage corridor" was introduced. This is a region where plumes are most likely to be found (based on global convection characteristics found from a simple superposition of cross-tail and corotational E- fields); the plasmaspheric drainage corridor is the global pathway for cold plasma to make its way to the dayside reconnection site. From simulation results, it may be that plumes affect the dayside reconnection rate most strongly for the strongest storms, which feature severe magnetopause contractions. Plasmaspheric models do a good job of predicting where and when plumes will occur, and what density they will have, but the structure inside plumes is not yet so well captured. The high degree of plasmaspheric and plume density structure (and sub-structure) was discussed in detail, and can arise from either rapid temporal variation of the solar-wind-driven E-field, or local inhomogeneity of the convection field; it is the latter effect in particular that is not yet well characterized enough for models to reproduce interior density structure. Interhemispheric asymmetries (linked to north-south asymmetry in the field-aligned flows), composition of the ionosphere, and kinetic processes add yet more complication to the density structure of the plasmasphere. Tuesday, 22 June 2010 PMI Breakout 4: 10:30am - 12:15pm. Topic: "Closing the Loop on PMI". After two spillover talks by Li and Dodger, the rest of this session was devoted to a detailed, in-depth discussion of the important topics and priorities of the Plasmasphere-Magnetosphere Interactions focus group, and how to address them in the remaining years of this effort. Talking points included: - The relationship of plumes to the global (and sub-global) features of convection that produce a corridor where dayside drainage plumes are likely to be found. - Comparisons between observations and our existing dynamic plume models, which do capture where and when plumes occur (in a global sense) but do not capture the structure inside of plumes, and also do not yet capture the dynamic, spatially-dependent refilling process accurately. - The integration of plume models into larger global circulation models. Several top PMI priorities were established for the next year of this focus group: (1) Plasmasphere/Plume internal structure should be a strong focus of attention. (2) We must get global MHD simulations to capture plasmaspheric dynamics. (3) The modeling of filling flux tubes needs to be improved significantly, and integrated into the overall modeling infrastructure. (4) The EMIC Wave Challenge. Led by Brian Fraser and Richard Denton, this will be a GEM-style challenge: to reproduce the spatial distribution, temporal dependence, and wave amplitude of EMIC waves. This will undoubtedly involve proper treatment of plasma composition, density, and Alfven waves. (5) GEM 2011 PMI Session on Ground Based Observations. At next year's GEM, PMI will host a special breakout session on ground-based observations of plasmaspheric densities. A handful of selected speakers will be invited. PMI Breakout 5: 1:30am – 3:00pm. JOINT SESSION with "Radiation Belts & Wave Modeling" (RBWM) focus group. For notes on this Joint Breakout, see report from the RBWM FG. Planned Activities: 2010 – 2011. There are numerous ongoing studies by researchers participating in the PMI FG. Coordination of these various studies will be via the PMI Wiki page (http://tinyurl.com/pmiFGwiki) and via the PMI Mailer List, which includes 71 people as of the writing of this report (with several joining after this year's workshop). The goal is to promote synthesis of the various studies into a system-level conceptual framework; PMI is by its very nature a system- level FG. We also plan to continue to recruit participation (in the form of crossover talks) in PMI from other focus groups whose topics overlap ours. We also will continue to solicit and encourage participation from other non-GEM disciplines such as CEDAR, thus promoting the system-level view of the geospace environment. As a result of the Group Discussion that took place at PMI Breakout 4 ("Closing the Loop on PMI"), the PMI focus group has established several priorities for the coming year, which are listed in the notes for Breakout 4 above. These priorities include several key physics topics, as well as the formulation of an EMIC Wave Challenge, and the resolution to hold a special Ground-Based Observations breakout session at GEM 2011. *** IMS FG on Radiation Belts and Wave Modeling (RBWM) Conveners: Yuri Shprits, Scot Elkington, Jacob Bortnik, and Craig Kletzing Session I Model development and validation. During the first session we discussed various acceleration mechanisms. We agreed, that we need to move from simply identifying potential candidates to quantifying different acceleration and loss mechanisms. We all agreed to make a list of mechanisms accounted for by different models and also a list of what different modeling groups are planning to include into their codes in the future. We decided to identify important mechanisms by performing a set of test simulates for a number of storms and also perform long term simulations of ~100 days when it's numerically possible. We decided to set up specific metrics that will be used for these GEM challenges. Session II Preparing Radiation Belt Models for RBSP Data. We discussed comparing models with observations and preparing models for observations. Virtual RBSP data for preparing models for RBSP data will be available soon. We had presentations from ECT; EMFASIS; RPS teams; We discussed what we can learn from models in preparation for RBSP. Session III Wave-particle interactions. We discussed observations and theoretical estimates of losses to the atmosphere. LASP group is working on measuring losses to the atmosphere and comparing them to theoretical quasi-linear lifetimes. We discussed non-linear effects and how they can be included into a global code and compared with observations. Session IV ULF. Discussions have been devoted to Shabanski orbits and their effect on the particle dynamics, theoretical study of waves produced by the variable solar wind dynamics pressure and observations of KH instability. Session V ULF/ VLF session. We discussed radial diffusion simulations, pic simulations of magnetosonic waves, self-consistent hybrid simulations of the excitation of EMIC waves. We also discussed how whistler mode waves may remediate the radiation belt hazard . Session VI We continued discussing VLF waves and looked at the statistical distribution of waves from different satellites that can be used for understanding of waves and statistical properties of waves. We discussed the DSX mission and it’s scientific objectives. Planning: We formulated 2 GEM challenges We chose data, time periods. Data and model results will be posted on the VIRBO web site. *** IMS FG on Space Radiation Climatology (SRC) Conveners: Paul O'Brien and Geoff Reeves The GEM Space Radiation Climatology Focus Group held three sessions, one joint with Radiation Belt/Waves. We heard project updates from LANL, UCLA, ONERA, and AE9/AP9. Of particular note is the recent beta release of AE9/AP9 to US Government and Contractors. We heard scientific talks on multiple topics, highlights follow: Proton belt dynamics exhibit systematic climatological features that cannot be explained easily (see Selesnick et al., JGR, 2010) Richard Denton has developed a full solar cycle of mass density at GEO. ViRBO is growing, and is prepared to help transfer our non-NASA data sets or derived data sets to NASA deep archives (e.g., NSSDC). LANL has developed new climatology models of GPS protons and LEO electrons. Themis SST data is usable for inner magnetosphere work, and a preliminary calibration has been done at UCLA (with caveats, of course) There are systematic spectral shapes in the outer zone electrons, and their occurrence frequency appears to be modulated by the plasmapause location. We are planning to collect and release ~6 month reanalysis data sets at Fall AGU. These data sets can be analyzied and results presented at the GEM Summer workshop. For more information, including selected presentation charts, visit http://virbo.org/GEM_FG9_2010 *** IMS/MIC FG on Diffuse Auroral Precipitation (DAP) Conveners: Richard Thorne and Joe Borovski The Diffuse Aurora Focus Group held 4 breakout sessions at the 2010 GEM meeting in Snowmass. The session topics and session chairs are listed below together with a brief summary of the topics discussed. 1. Relationship between auroral phenomenology and scattering mechanisms. Monday June 21: 10:30-12:15: Co-chairs, Binbin Ni (bbni@atmos.ucla.edu) and Robert Michell (rmichell@swri.edu) Topics: * Relative role of ECH and chorus scattering at different locations and activity levels * Formation of observed electron pancake distributions due to chorus scattering * Temporal variability of DA up to 10 Hz: related to chorus elements? 2. Modulation of DA brightness by large-scale magnetospheric processes. Monday June 21: 1:30-3:00: Co-chairs, Marilia Samara (marilia.samara@swri.org) and Jacob Bortnik (jbortnik@gmail.com ) Topics: * Modulation of chorus emissions by large-scale magnetospheric density and magnetic field structures: possible relationship to DA spatial features. 3. Spatial and temporal extent and spatio-temporal occurrence of DA/scattering mechanisms. Monday June 21: 3:30-5:00: Co-chairs, Toshi Nishimura (toshi@atmos.ucla.edu) and Richard Thorne (rmt@atmos.ucla.edu) Topics: * Statistical survey of DA variability from ground based auroral images. Pulsating aurora dominant over equatorial edge of DA zone at periods between 5-10 s. * Strong correlation between DA pulsations seen by the THEMIS ASI images and chorus modulation observed directly on THEMIS spacecraft. 4. Importance of DA for Geospace at the system level. Tuesday June 22: 10:30-12:15: Chair, Richard Thorne (rmt@atmos.ucla.edu) Topics: * Formulation of a campaign to identify global DA periodicity and compare with THEMIS wave observations. *** IMS FG on Near Earth Magnetosphere: plasma, fields, and coupling Conveners: Sorin Zaharia, Stan Sazykin and Benoit Lavraud The Near-Earth Magnetosphere focus group held 3 breakout sessions at the 2010 GEM Summer Workshop in Snowmass, CO. The main goal of the focus group is to improve our physical knowledge and modeling of the near-Earth magnetosphere and its coupling with the outer magnetosphere. The focus group is coordinated by Sorin Zaharia, Stan Sazykin and Benoit Lavraud. The three focus group sessions, held on Wednesday and Thursday (06/23- 24) featured short presentations and discussions related to the following scientific research topics: 1. Inner-outer magnetosphere coupling: * Effect of depleted entropy bubbles on the inner magnetosphere as obtained from a 3D MHD simulation (J. Birn) * Coupling of Rice Convection Model (RCM) with a global MHD code: interchange-related dynamic flows and oscillations; plans to modify RCM to include inertial terms (F. Toffoletto) * Effect of ion outflow on ring current (through plasma sheet density/temperature, cross polar cap potential drop and ion composition) (D. Welling) * 1-way coupling of the BATS-R-US global MHD code with the Comprehensive Ring Current Model (CRCM) and Radiation Belt Environment (RBE) codes; importance of electric field self-consistency (Q. Zheng) * Specification and effect of plasma properties at geosynchronous orbit in RCM; ring current dependence on ionospheric conductivity (M. Gkioulidou) 2. Observational studies and empirical models: * Empirical magnetic field modeling – modification of the T96 model by adding a substorm current wedge; importance of magnetic field model for M-I coupling (G. Lu) * Results from the TWINS mission; stereoscopic ion inversion providing pitch angle information; validation vs. THEMIS data; presentation of available TWINS data products (J. Goldstein) * Exploring plasmaspheric subcorotation through radar observations (Blackstone –mid-latitude) of westward flows on field lines mapping into the plasmasphere (L. Claussen) 3. Interaction between plasma and fields in the near-Earth magnetosphere - coupling between different elements in numerical models (plasma, electric and magnetic fields): * Two presentations accompanied by spirited discussions on comparisons of different formalisms for studying plasmas: MHD, guiding center and Vlasov theory (R. Strangeway); differences between single-fluid MHD and kinetic formalisms, and what one needs to add to MHD in order to reproduce inner magnetosphere physics (S. Zaharia) * Effect of self-consistency/stretched magnetic fields on ring current morphology and dynamics (V. Jordanova; R. Ilie) * Importance of self-consistent treatment of particles and fields in the storm-time inner magnetosphere, explored through comparison of simulated and observed magnetic intensities and ion plasma parameters from GOES, Polar, LANL (M. Chen) * Simulation of Steady Magnetospheric Convection (SMC) event with RCM- E needs to be driven with depleted flux tubes in order to reproduce THEMIS observations (F. Toffoletto) The second half of the 3rd breakout session was devoted to a community discussion on future plans for Focus Group activities. A list of tentative topics emerged regarding breakout sessions at the 2011 GEM Summer Workshop: 1). Simulate events in the GGCM Modeling Challenge/calculate observable metrics; 2). Obtain fields/plasma conditions with applications to radiation belts/inner magnetosphere waves; 3). Obtain electric field maps with applications to plasmasphere physics; and 4). Conclude Phase 1 of the Near-Earth Magnetosphere Challenge, involving the simulation of an idealized geomagnetic storm. The above topics will be further refined at a Mini-workshop session that the focus group intends to organize before the 2010 AGU Fall Meeting in San Francisco. Some of the sessions above could be organized as joint sessions with other relevant focus groups. Finally, the discussion steered toward ideas for wrapping up the focus group activities in 2012. Starting from the focus group proposal approved by the GEM Steering Committee, several possible deliverables as the outcome of the focus group were discussed, to be conveyed through various media: a final report or a review paper (with individual papers attached), as well as publication on the Web; these deliverables would include: * A description of progress in inner magnetosphere physics undergone under the focus group * A list of inner magnetosphere models, improved physics features and couplings developed * Physics results from the Near-Earth Magnetosphere Challenge; a comparison of different models and a discussion of the effects of different physics features through simulating both an idealized (Phase 1) and real (Phase 2) geomagnetic storm. +-------------------------------------------------------------------+ | To subscribe GEM Messengers, send an e-mail to | | | | with the following command in the body of your e-mail message: | | subscribe gem | | To remove yourself from the mailing list, the command is: | | unsubscribe gem | | | | To broadcast a message to the GEM community, please contact | | Peter Chi at | | | | Please use plain text as the format of your submission. | | | | GEM Messenger is also posted online via newsfeed at | | http://heliophysics.blogspot.com and | | http://www.facebook.com/heliophysics | | | | Back issues are available at ftp://igpp.ucla.edu/scratch/gem/ | | | | URL of GEM Home Page: http://aten.igpp.ucla.edu/GemWiki | | Workshop Information: http://www.cpe.vt.edu/gem/index.html | +-------------------------------------------------------------------+