*************************** ** THE GEM MESSENGER ** *************************** Volume 14, Number 40 August 10, 2004 ----------------------------------------------------------------------- Report on Inner Magnetosphere/Storm Campaign Activities At the GEM 2004 Workshop, Snowmass, CO, June 21-25 ----------------------------------------------------------------------- From: Mike Liemohn , campaign chair Margaret Chen , WG-1 chair Dennis Gallagher , WG-1 chair Richard Thorne , WG-2 chair Reiner Friedel , WG-2 chair Mark Moldwin , WG-3 chair Brian Fraser , WG-3 chair Paul O'Brien , session convener Vania Jordanova , session convener Ian Mann , session convener Jerry Goldstein , session convener Janet Green , session convener Scot Elkington , session convener Mary Hudson , session convener Joe Borovsky , session convener Ennio Sanchez , session convener Mike Henderson , session convener Bob Clauer , session convener The Inner Magnetosphere/Storms Campaign held 13 quarter-day oral sessions at the GEM 2004 Workshop in Snowmass, CO, in late June. The IM/S Campaign also had two invited tutorial presentations and dozens of presentations at the Tuesday evening poster session. The IM/S Campaign is focused on understanding the physics of the inner magnetosphere and defining the key elements necessary for simulating the near-Earth plasma populations as part of a Geospace General Circulation Model (GGCM). The campaign has 3 working groups: Plasmasphere and Ring Current (WG-1), Radiation Belts (WG-2), and ULF Waves (WG-3). The IM/S Campaign officially began in 1999 and is expected to end with the 2006 summer workshop. The climax of the IM/S Campaign is the IMS Assessment Challenge, in which several time intervals have been chosen for intensive data-model comparisons. Working groups 1 and 2 are each conducting their own versions of this challenge. Initial results for the WG-1 challenge were presented at this workshop, and the planning for the WG-2 challenge was discussed in detail in Snowmass as well. WG-3 is intimately involved with both the WG-1 and WG-2 challenges. The following is a summary of each of the sessions, in the order in which they occurred during the workshop. For the most part, these were written by the session conveners. ----------------------------------------------------------------------- Report on Inner Magnetosphere/Storm Campaign Invited Tutorials ----------------------------------------------------------------------- The IM/S session had two invited tutorial presentations: on Monday and Tuesday mornings by Jerry Goldstein and Geoff Reeves, respectively. Jerry discussed "Plasmasphere/Plasmapause Dynamics", posing the question of what is needed in a plasmaspheric model for the GGCM. In particular, he examined IMAGE EUV data to explain how convection fronts alter the distribution of cold plasma in the inner magnetosphere, first impacting the midnight region and then propagating toward the dayside. He also showed that the quiet time plasmasphere tends to develop more small-scale structure that during active times. Geoff Reeves presented "Progress and Challenges in the GEM Radiation Belt Investigations". Opening with the GEM Invited Tutorial Filter, he then proceeded to discuss what has been learned about the radiation belts in recent years. The concluded by presenting some new directions in radiation belt analysis, particularly emphasizing global modeling and data assimilation. He emphasized that knowledge of the inner magnetospheric magnetic field topology is still a large source of uncertainty in understanding radiation belt observations. ----------------------------------------------------------------------- Session Summary: "GEM Storms Analysis" (WG-1, 2, and 3) Conveners: Ian Mann and Mike Liemohn ----------------------------------------------------------------------- This session was dedicated to the analysis of the GEM-Storms events: May 15, 1997; September 25, 1998; October 19, 1998; October 4-6, 2000; March 31-April 2, 2001; October 21-23, 2001; and April 17-24, 2002. The recent ¡§Halloween¡¨ superstorms were also added to the list of preferred events. The full slate of speakers and the rich and lively discussion demonstrated the vitality of the community-wide effort to examine and understand the GEM-Storms events. The interest was so high that several talks had to be rescheduled to other sessions later in the week. Here is a brief synopsis of the session. Wendell Horton presented a very fast, simple model to predict the magnitude of several current systems during substorms, and applied it to all of the GEM-storm events. Zoe Dent examined field-line resonance cross-phase analyses for some of the events, finding that the predicted mass density is sensitive to the assumed B-field model and that much of the diurnal variation is due to local-time-dependent stretching. Joe Fennel showed pitch angle distributions for some of the GEM-storm events, concluding that field-aligned ions appear deep within the inner magnetosphere at energies below 10 keV, but are separate from the main ring current peak. In analyzing the April 2002 event, Shin Ohtani found that dipolarizations are well correlated with oxygen ENA enhancements. Gang Lu then showed AMIE results for the GEM-storms events, highlighting the relationships between IMF and geophysical quantities extracted from AMIE. For the Halloween storms, the polar cap potential reached 400 kV and the Joule heating exceeded 5 TW, which are some of the largest values Gang has seen in the AMIE results. The rest of the talks focused on the Halloween storms. Dan Baker presented SAMPEX data of the radiation belts, noting that these storms had fluxes 2 orders of magnitude bigger than anything else in the SAMPEX database at L=2. Xinlin Li then shoed his prediction model results, showing that the March 2001 superstorm actually had a more dramatic and longer lasting inner belt than the Halloween storms. Richard Thorne showed diffusion modeling results that predict chorus wave interactions can fill the slot region within 1 day. Cheryl Huang presented a detailed study of the DMSP observations of cold ions at low L shells, seen more dramatically in the morning sector. The talks by Peter Chi, Sebastien Bourdarie, and Ian Mann were moved to other relevant sessions later in the week. ----------------------------------------------------------------------- Session Summary: "Plasma Transport into the Inner Magnetosphere: SMC Conditions Versus Other Conditions" (WG-1 and WG-2) Conveners: Ennio Sanchez and Joe Borovsky ----------------------------------------------------------------------- Preliminary evidence indicates that the transport of plasma into the inner magnetosphere during SMC (Steady magnetospheric convection) events is unusually efficient. This could be caused by more-efficient transport of plasma or by stronger sources of plasma. In this session, data analysis and theory presentations were given to explore this issue. In particular the session focused on the following four questions. (1) Can we quantify the transport of plasma into the inner magnetosphere for SMC versus other conditions? (2) Is convection in the magnetosphere higher than "normal" during SMC times? (3) If convection is higher, is it because BBFs are occurring more frequently or is it because the underlying slow convection is stronger than "normal". (4) Are the sources of plasma (solar wind entry, ionospheric outflow, plasmasphere, etc.) enhanced during SMC events. After several presentations, an open discussion was conducted to further examine these questions and the SMC phenomenon. ----------------------------------------------------------------------- Session Summary: "GEM IMS Challenge: Data" (WG-1 & WG-3) Conveners: Mark Moldwin and Dennis Gallagher ----------------------------------------------------------------------- The intent of the data session was to draw together available measurements for the IM/S GEM Challenge storms for the purpose of supporting quantitative evaluation of the state of inner magnetospheric modeling. While the approach to establishing the contribution of the IM/S campaign to the GEM program was decided at the previous December mini-GEM at Fall AGU, relatively few observations of the inner magnetosphere have been assembled. A description of the IM/S challenge with links to relevant Internet sites can be found at http://csem.engin.umich.edu/GEM_IMS/. Measurements and empirically derived physical properties of inner magnetospheric plasma are being made available on originating institution web sites and on a common FTP site at ftp://ftp.nsstc.nasa.gov/GEM. While not complete, a variety of measurement sources and analysis techniques were presented in this session. Richard Denton presented a Polar spacecraft derived power-law model for the distribution of thermal plasma along magnetic field lines. He also showed evidence from the CRRES spacecraft for increasing density toward the magnetic equator along field lines. Jerry Goldstein presented an overview of plasmapause determinations for the challenge storms. These results and information that can be used to estimate a component of the convection electric field during the events are available on the WG1 FTP site. Michael Denton discussed the results of comparing IMAGE spacecraft MENA (medium energetic neutral atom) ring current observations with models by Jordanova and Liemohn. The comparison was done using MENA images and simulating MENA images from the theoretical models. Peter Chi described a relatively new technique that is now starting to be applied. Field line resonances are inverted in order to derive mass density distribution. The method has been coined magnetoseismology. Another useful source of magnetic field measurements that was presented is from the Polar (or other) spacecraft, which can be used to obtain magnetic field perturbations, hence currents, and magnetic field oscillations from waves. The spatial and temporal variations of currents and wave amplitudes are important measures of energetic plasma processes. Dave Berube described a new automated process for obtaining the same magnetoseismology results that may replace the labor-intensive method now being used. Howard Singer described the availability of GEOS satellite measurements for obtaining field line currents in the tail, ring current, and magnetopause. Bob Clauer discussed how the axial component of the magnetic field would be used to "see" the partial ring current development. Shortly after the June GEM workshop Tony Mannucci provided global ground- based TEC data in support of GEM storm October 21-22, 2001. Files and documentation are now available on the challenge FTP site. ----------------------------------------------------------------------- Session Summary: "GEM IMS Challenge: Modeling" (WG-1 & WG-3) Conveners: Margaret Chen and Jerry Goldstein ----------------------------------------------------------------------- This IM/S GEM Challenge Modeling Session focused on comparing ring current, plasmaspheric, and ionospheric model results with observations for the two storm challenge events. Vania Jordanova presented results from her version of the Ring-Current Atmospheric Model (RAM) that used both the Volland- Stern and Weimer models of electric field convection for the 21-23 October 2001 storm. With the Weimer electric field her model produced better agreement with the observed Dst and with the high altitude NOAA-15 data than with the Volland-Stern electric field. With either of these electric field models, she found good agreement between her model ion fluxes and in- situ Polar and Cluster fluxes but not good agreement with the proton fluxes inferred from HENA images. Natalia Ganushkina showed calculations of the energy density of ring current protons with energies ranges of 1-20 keV, 20-80 keV, and 80-200 keV from her ring current model that takes into account the effect of substorm-associated electric and magnetic field pulses. Often she finds that during the storm recovery phase that the higher energy protons contribute more to the energy density than the lower energy ions. However, the high-energy protons did not dominate the contribution to the energy density during the recovery phase of the 21 October 2001. Xinlin Li described his Dst prediction model. The Dst index for the two challenge storms are quantitatively reproduced by using solar wind parameters. Mike Liemohn performed simulations of the ring current and plasmasphere using his version of the RAM model with 4 different electric field models: (1) Volland-Stern, (2) modified McIlwain, (3) self-consistently computed cross polar cap potential with field-aligned currents from RAM, and (4) self-consistently computed cross polar cap potential with double the auroral oval conductance. He compared his model results to Dst, mid-latitude magnetic field perturbations, LANL/MPA data, and EUV, MENA, and HENA images. A red, yellow, green light scale to indicate how well the model agreed with all the data sets was displayed in a matrix. Overall, he found that the Volland-Stern model is not bad. However, the self-consistent electric field generally produced model results that were in better agreement with the observations. Steve Naehr illustrated how synthetic ENA images can be produced from the Rice Convection Model¡VEquilibrum (RCM-E) and compared with HENA images. He emphasized that forward modeling can be very useful because it avoids image inversion difficulties. Naomi Murayama described a new model that she is developing that includes both plasmaspheric refilling and the evolution of the plasmapause. She has found good agreement of the electron densities from her model with Carpenter's measurements. Her model will be used to evaluate the refilling time scale, the required heating rates, flux tube depletion, zonal plasma motion, and the details of the plasmapause formation process. Jerry Goldstein very briefly showed a simulation of the 22-33 April 2001 plasmasphere erosion, using a Volland-Stern E-field normalized to 20% of the solar wind E-field. The simulation agreed with EUV images on a global scale, but indicate the need for more complete understanding of the sub-global E-field. ----------------------------------------------------------------------- Session Summary: "Analysis of Electron PSDs During Storms" (WG-2) Conveners: Janet Green and Reiner Friedel ----------------------------------------------------------------------- The flux of relativistic electrons (>~100keV) in the outer radiation belts varies dramatically on timescales of less than a day. Many theoretical mechanisms have been developed to explain the rapid acceleration of electrons to these high radiation belt energies but as of yet none has been definitively confirmed by observations. The various mechanisms proposed make specific and testable predictions about how the electron phase space density is expected to evolve as a function of both time and L-shell as electrons are accelerated. However, any comparison to these predictions requires transforming electron flux measured as a function of position, energy, and pitch angle to phase space density (PSD) expressed as a function of the three adiabatic invariants, mu, K, and L*. The results of such comparisons are often ambiguous because of large errors introduced by the transformation of the data. In this session, work was presented showing new methods for calculating PSD, phase space density gradients obtained from a variety of datasets, and new theoretical modeling results. The session began with an introductory talk from Geoff Reeves who reviewed past work and highlighted how errors are introduced by the transformation of the data to PSD. All PSD calculations suffer from errors introduced by the necessary reliance on magnetic field models of unknown accuracy to calculate the electrons second and third adiabatic invariants. Terry Onsager showed a new method for calculating the radial gradient of PSD using the two geosynchronous GOES satellites. The model relies on the fact that the two satellites, located at the same radial distance (6.6), actually sample different L shells because of their differences in local time and latitude. Using deduced pitch angle distributions, an outward radial gradient was obtained for one time period during fairly quiet magnetospheric conditions. Yue Chen showed PSD gradients obtained from the LANL geosynchronous data using a variant of the method described by Onsager. Pitch angle distributions were obtained by using lower energy particle measurements to determine the direction of the magnetic field. The results of this careful work showed that during two events the PSD increased first with an outward radial gradient and then developed into a peak at L~6 as electrons were lost at higher L. Joe Fennell showed PSD gradients obtained from the SCATHA satellite in a low inclination orbit covering L ranges from ~4.5 to ~7. Surprisingly, the results showed the electron PSD increases rapidly and uniformly at all L values sampled with an approximately flat gradient. Some modeling work was presented by both Sebastien Bourdarie and Sasha Ukhorskiy. Sebastien showed some of the new improvements made to the Salammbo code which solves a diffusion equation that includes both pitch angle and radial diffusion. The model has been adapted to include a simple form of data assimilation. Sasha showed progress with the development of a new radial diffusion code. A comprehensive explanation for the myriad of PSD observations is still elusive but will likely come as a result of the new GEM challenge which will be a coordinated effort to calculate PSD during one or two events using all data available and implementing the new more precise calculation methods. ----------------------------------------------------------------------- Session Summary: "ULF Heating and Transport" (WG-2 and WG-3) Conveners: Mary Hudson and Brian Fraser ----------------------------------------------------------------------- John Freeman opened the session discussing the response of the magnetosphere to an idealized synthetic oscillatory solar wind driver at 3mHz sustained for some 2500s. It was concluded that the simulation of large-scale ULF waves from a variety of solar wind drivers can provide insight into energy transmission processes and wave structure in the magnetosphere. Scot Elkington explained how drift resonance driven by fluctuations in the convection electric field might accelerate electrons in a compressed dipole. Whether acceleration can occur is dependent on the propagation characteristics of the waves. Following on from the previous paper, Ian Mann discussed the need for a ULF wave index for use in statistical studies of radiation belt dynamics and electron acceleration. He pointed out that Dst is a poor indicator and it is important to determine the appropriate ULF waves to monitor. ULF wave power and Vsw were shown to be better indicators. Further work is needed to cross-calibrate in situ and ground based measurement techniques. Frank Cheng considered the topic of proton heating during substorms, including stochastic wave growth. In particular, diffusion and perpendicular heating were discussed. Modeled radial diffusion computations were compared with CRRES results by Yuri Shprits. For a time dependent radial diffusion model it was found that the 1-10 day lifetimes were important. The model reproduces 0-150 days of CRRES data and follows the lower electron flux edge in L quite well. It reproduces some storms well, but not all. Theodore Sarris considered compressional oscillations propagating into the magnetosphere and the magnetic field response at synchronous orbit. He investigated diffusion in particle populations for various levels of magnetic activity and found that D_LL calculations followed the earlier results of Falthammar. Kara Perry introduced a 3-dimensional radiation belt model with diffusion included to characterize ULF wave observations. The slope of ULF wave power dependence on frequency and L value were found to have important effects on D_LL. A much stronger L dependence results when L-profiles of ULF wave power measured by ground magnetometers are used in the model. CRRES electric field ULF wave data with both high and low wave numbers were analysed by Sasha Ukhorskiy. Wave-particle interaction involving poloidal mode waves and particle tracing at the equator provided diffusion coefficients for the poloidal mode and the toroidal mode. ----------------------------------------------------------------------- Session Summary: "Sawtooth Events" (WG-1 & WG-2) Conveners: Mike Henderson and Bob Clauer ----------------------------------------------------------------------- Sawtooth events are quasi-periodic, large-amplitude flux oscillations with a periodicity of 2-4 hours observed globally at geostationary orbit. The oscillations have been termed 'sawtooth events' because their shape -- a series of slow flux decreases followed by rapid increases -- resemble the teeth of a saw blade. The 'sawtooth' shape is particularly well-defined in energetic proton fluxes. They occur during storms when the ring current is enhanced and they appear to be driven by steady, moderate to strong, southward IMF conditions (magnetic clouds). The plasma sheet appears to be unusually close to the Earth at the time of sawtooth events and the inner magnetospheric plasma convection is strong. Although each 'tooth' of a sawtooth event exhibits many of the characteristics that one would normally associate with substorms (e.g. field stretching and dipolarization, particle injections, auroral onsets, etc.), the disturbances rapidly engage a wider than usual range of magnetic local time sectors and the dipolarization and dispersionless injection signatures can extend past the terminators into the dayside. This and other considerations have raised issues regarding the nature of substorms, storm-time substorms, steady magnetospheric convection events, direct driving vs. unloading, the inner magnetospheric pressure catastrophy, magnetospheric convection and energy dissipation. This session focused on the following issues: (1) establish more fully the observational characteristics of sawtooth events and to (2) address theoretical physical mechanisms that might explain their occurrence. Among the questions that need to be addressed more fully are: Do sawtooth events form a specific class of substorms? How does the tail behave during sawtooth events? What does the ring curent look like (asymmetry, composition, radial structure, etc.) during sawtooth events? Why doesn't the steady solar wind conditions that drive sawtooth events not produce steady magnetospheric convection (SMC) events instead? What current systems are responsible for the observed field changes on the ground and in space? Why are the injections so energetic (especially in protons)? Several presentations were made, showing data and modeling results of sawtooth oscillation events. Many different opinions exist regarding these events, and a lively discussion concluded the session. Resolution on the issues was not reached, but additional sessions, and GEM and other workshops, are planned to continue the debate. ----------------------------------------------------------------------- Session Summary: "Quantification of Electron and Ion Loss Rates from the radiation Belts" (WG 2&3), chaired by Richard Thorne and Paul O'Brien ----------------------------------------------------------------------- Janet Green discussed the sudden loss of relativistic electrons: drops by a factor of 100 in >2 MeV electron flux at GEO. Similar dropouts are also seen down to L=4 on HEO satellites and occur down to energies of 300 keV. POES sees electron precipitation at 17-4 MLT. Several mechanisms were discussed as possible causes for the sudden loss. The analysis suggests that EMIC are the most likely mechanism, but local time inconsistency must be resolved. Reiner Friedel presented a superposed epoch analysis of the rapid dropouts, using GPS data. The dropout were found to extend down to L=4.8. The dropout appears to occur slower at higher energy and lower L. Robyn Millan considered the relation ship between microbursts (caused by chorus), MeV X-ray bursts observed on MAXIS balloon observations, GOES rapid dropouts, and SAMPEX precipitation bands all seen at the same time during the MAXIS flight. She asked whether they are they related. She questioned whether drift dispersion can smear out the rapid microburst and other temporal signatures in the precipitation flux. Dan Baker presented data on the Halloween storms and showed that the post- storm decay occurred on timescales comparable to 3-5 days for two penetration events that injected energetic electron into L=2.5 (the normal location of the quiet time slot). Richard Thorne described how the microburst loss rates depend on pitch- angle scattering rates near the edge of the loss cone. He presented data from SAMPEX observations, which suggest that microburst loss rates during the main phase of a storm occur with a lifetime comparable to 1 day. He presented theoretical calculations which also indicated a lifetime comparable to a day gives about 1 day for low density conditions expected outside the plasmapause during the main phase of a storm. Recent work by Jay Albert (presented by RMT) on the scattering of energetic electrons by storm-time enhanced plasmaspheric hiss can reduce MeV electron lifetimes to a few days. When additional scattering due to EMIC waves during main phase are included the combined lifetime can drop below 1 day. Brian Fraser discussed GOES observation of EMIC waves associated with detached proton arcs and cold plasma seen by LANL. Such waves provide an important ring current loss process. Vania Jordanova described results from her kinetic code, which indicated that EMIC induced ion scattering losses maximize during the main phase of a storm, and can remove ions at a comparable rate to charge exchange during the main phase. ----------------------------------------------------------------------- Session Summary: "Radiation Belt Ideas for the GEM Challenge" (WG-2) Conveners: Richard Thorne and Reiner Friedel ----------------------------------------------------------------------- This session was for the Radiation Belts working group to discuss ideas regarding the implementation of a relativistic electron IMS Assessment Challenge. Presentations were made regarding the best course to follow and the interval to select, but much of the session was devoted to an open discussion to formulate a proposed plan. A tentative schedule for the year ahead was designed, with the following elements: (1) an email discussion in late summer/early fall to decide on time intervals; (2) magnetic field modeling of the events during the fall; (3) magnetic field modeling results and initial data analyses presented at the mini-workshop in December; (4) a WG-3 only special workshop in late winter/early spring to present initial results and decide future plans; and (5) presentation of final results at next summer's GEM workshop. The timeframe might slip into the next year, but the deadline of June 2006 for the end of the IMS Campaign is impetus to proceed as scheduled with this phase of the IMS Challenge. ----------------------------------------------------------------------- Session Summary: "ULF Diagnostics" (WG-3) Conveners: Mark Moldwin and Brian Fraser ----------------------------------------------------------------------- This break-out session was sponsored by the new ULF Waves working group within the Inner Magnetosphere/Storms Campaign. WG 3 is devoted to the study of the role of ULF waves in particle acceleration, loss, and transport. The session on "ULF Diagnostics" discussed the different techniques that can be used to infer important properties (e.g., mass density, the location of the plasmapause, etc.) of the inner magnetosphere from both ground-based and space-based instruments. The international effort to develop a ULF wave index was also discussed. This session showed that the techniques are maturing and that there is considerable potential for routine monitoring of the mass density and plasmapause location using meridional arrays of magnetometers. Specifically, Jerry Goldstein presented a talk titled, "Plasmaspheric Density Distribution Determined by Cross-Comparison of EUV Images and LANL or RPI In Situ Measurements" in which he showed the first steps of calibrating the IMAGE EUV images to in situ observations. In general, IMAGE EUV has a threshold of approximately 30 ions per cc. Peter Chi presented a talk titled, "Observations of Field Line Resonance Properties and Magnetospheric Density by Joint Operation of Magnetometers at the 330th Magnetic Meridian" in which he showed results from the Halloween storm using the APGM method. Zoe Dent presented a talk titled, "Monitoring Heavy Ion Dynamics via Comparison of Ground-Based Magnetometer and IMAGE RPI Observations" where she estimated the contribution of heavy ions in the plasmasphere following storms. Dave Berube gave a presentation titled, "Plasmaspheric Mass Density Response to GEM Storms Determined from ULF Resonance Measurements" where he compared the different field line resonance techniques. He found that the combination of the cross-phase and amplitude method works as well as the APGM method with the advantage of a quantitative uncertainty of the estimate. Richard Denton spoke on the "Mass Density Determination using Spacecraft Data." Richard presented CRRES data of multi-harmonic ULF resonances that were used to constrain the field line distribution of mass density. Hedi Kawano described results regarding the "Remote Sensing the Plasmasphere with the CPMN Japanese Chain." By using a meridional chain of stations, the location of the plasmapause can be estimated using field line resonance observations. Finally, Brian Fraser presented work of Fred Menk's showing ULF resonance observations that were used to track mass density behavior and the motion of the plasmapause. ----------------------------------------------------------------------- Session Summary: "IMS Theory and Modeling" (WG-1, 2, 3, and GGCM) Conveners: Vania Jordanova and Scot Elkington ----------------------------------------------------------------------- This session was held in collaboration with the GGCM campaign. It spanned two quarter-day sessions on Tuesday afternoon and Wednesday morning. The first part of this session focused on new theory and modeling applications in the inner magnetosphere. New results from storm time magnetic field modeling were presented by Margaret Chen, Sorin Zaharia, and Natalia Ganushkina. They indicated that the inner magnetosphere magnetic field differs significantly during storm time from a dipolar configuration and strongly influences both the ion and electron ring current evolution. A new relativistic quasilinear diffusion tensor for arbitrary-frequency electromagnetic perturbations was presented by Anthony Chan, while Bob Lysak showed new results from global modeling of ULF waves in the inner magnetosphere. Richard Thorne and Yuri Shprits showed simulations of the energy and pitch-angle diffusion by chorus emissions and the subsequent filling of the slot region during the Halloween storms, in good agreementwith observations. The SEP injection in the inner zone proton belts during storms was discussed by Brian Kress, and Austin Baker presented relativistic electron fluxes obtained with a radial diffusion model. During the second part of this session, which focused on how the current state of inner magnetospheric modeling fits in with the goals of developing a GGCM, Frank Toffoletto discussed the coupling of the RCM to the LFM models and Aaron Ridley showed the recent development of the CSEM model. The session ended with a general discussion on what advances or directions need to be taken for further improvement of our modeling efforts. It was indicated that the global MHD models are fairly robust and can implement various inner magnetospheric modules, like models of the ring current, the plasmasphere, and the radiation belts. Comparing results from such investigations will help identify various models' strengths and weaknesses. ----------------------------------------------------------------------- Session Summary: "IMS Challenge: Assessment and Future Plans" (WG 1,2,3) Conveners: Mike Liemohn and Dennis Gallagher ----------------------------------------------------------------------- This session was devoted to recapping the progress made at the workshop towards defining and conducting the IM/S Assessment Challenge, and to discuss the plans for the year ahead regarding this endeavor. Reiner Friedel gave a summary of Tuesday¡¦s discussion to plan out the radiation belt phase of the challenge. Mike Liemohn also gave a very brief review of the plasmasphere and ring current results presented on Monday. This was followed by several talks focused on quantitative metrics for data- model comparisons, given by Elly Huang, Lutz Rastaetter (for Kristi Keller), and Joerg-Micha Jahn. There was also a discussion of what to do by next December (at the GEM Mini-Workshop prior to the Fall AGU Meeting) and by next June (the summer 2005 Workshop). It was decided that most of the effort this year would go towards the radiation belt phase of the challenge, with definitive plans agreed upon by December, initial results at a dedicated workshop (sponsored by IGPP?) in late winter/early spring, and refined results for all phases of the challenge presented in Santa Fe next June. Time was also spent discussing the specific data sets to "officially" include in the challenge. In a brief meeting after the session, the data sets for the ring current were agreed upon. Data for the plasmasphere and radiation belts will be decided during the year ahead. +-------------------------------------------------------------------------+ |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. | | | |URL of GEM Home Page: http://www-ssc.igpp.ucla.edu/gem/Welcome.html | |Workshop Information: http://gem.rice.edu/~gem | +-------------------------------------------------------------------------+