Table of Contents ====================================================================== 1. Workshop Report: Plasmasphere Magnetosphere Interactions (PMI) Focus Group 2. Workshop Report: Nonlinear Plasma Effects in Auroral/Subauroral Plasmas 3. JOB OPENING: 3 Post-doc Positions at IRAP, Toulouse, France ====================================================================== *************************** ** THE GEM MESSENGER ** *************************** Volume 21, Number 28 October 20, 2011 ---------------------------------------------------------------------- 1. Workshop Report: Plasmasphere Magnetosphere Interactions (PMI) Focus Group ---------------------------------------------------------------------- Focus Group Leaders: J. Goldstein, M. Spasojevic, J. Borovsky Plasmasphere Magnetosphere Interactions (PMI) Focus Group How Are Magnetospheric Processes Regulated By Plasmaspheric Dynamics (and Vice Versa)? 2011 Focus Group Report Conveners: J. Goldstein, M. Spasojevic, J. Borovsky Wiki: http://aten.igpp.ucla.edu/gemwiki/index.php/FG11._Plasmasphere- Magnetosphere_Interactions ABRIDGED LINK: http://tinyurl.com/pmiFGwiki Purpose of This Document This is a report of activities of the Plasmasphere-Magnetosphere Interactions (PMI) Focus Group (FG) at the 2011 Geospace Environment Modeling (GEM) Workshop in Snowmass, Colorado. This report presents a broad overview of the physical ideas discussed rather than a detailed summary of each and every presentation. The report is posted online at the GEM PMI Wiki page: http://tinyurl.com/pmiFGwiki. 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 all attendees and speakers. PMI Breakout Sessions To address the PMI FG's central question, "How Are Magnetospheric Processes Regulated By Plasmaspheric Dynamics (and Vice Versa)?" we hosted three (3) Breakout sessions at the 2011 GEM Summer Workshop: * PMI-1: Plasmaspheric Density Structure and Dynamics (~30 people attending); * PMI-2: Wave-Particle Interactions (~50 people attending); * PMI-3 (Joint w. CEDAR): M-I Coupling in the Plasmaspheric Boundary Layer (~30 people attending). The detailed schedule (GEM_PMI11_final.pdf) is posted on the PMI Wiki. These PMI Breakout sessions were quite well-attended (on average, ~36 people per session), and there was generally a great deal of animated discussion. Directly below, each PMI Breakout Session is listed with its Topic, followed by a brief summary of what was discussed and accomplished at the session. Monday, 27 June 2010 PMI Breakout 1: 16:00-18:00. Topic: "Plasmaspheric Density Structure and Dynamics". This session featured seven (7) scheduled presentations by Moldwin (INVITED), Chappell, R. Denton, Brandt, Goldstein, Ozhogin, and Foster. Modeling of the formation, evolution, and morphology of plasmaspheric density was discussed in a historical context, and it was agreed that the next generation of models must incorporate sub-global structure, and account for dynamics on longer time scales, especially during and after the recovery phase. Significant discussion dealt with possible formative mechanisms of the plasmaspheric "armpit", i.e., global density depletion inside and west of the base of an afternoon-sector plume, with a likely candidate being a combination of the natural corotation of plasma plus a sub-global duskside eddy flow whose existence is merely postulated (as it would be consistent with EUV- observed eddy-like motions of cold plasma in this region). Plume shredding was also discussed, motivating the conclusion that modelers need to think about how to put more structure into the plume. Refilling rates were modeled, and cross-comparison between active radio sounding by RPI and geostationary observations (in the literature) was performed. Field aligned density profiles were also extracted from RPI radio sounding measurements, and some MLT and/or longitudinal effects were identified for further investigation. Similarly, from TEC observations (which are believed to be roughly 50% from the plasmasphere and 50% from the ionosphere) some clear UT and longitudinal effects were identified for investigation and explanation, with the SMA being a possible candidate. At the end of this session, an eigth (8th) impromptu presentation by Shepherd highlighted the capabilities of the NSF-funded SuperDARN radars, and the new MSI stations coming online. Tuesday, 28 June 2010 PMI Breakout 2: 10:00-12:00. Topic: "Wave-Particle Interactions". This session featured eight (8) scheduled presentations by Bortnik (INVITED), R. Denton, Blum, Chen, Jordanova, Lio, Zhang, and Foster. Ray tracing modeling of hiss and chorus was presented, showing fairly good agreement with observed wave dynamic spectra, and suggesting the conclusion that cold plasma can exert significant control on wave power, and on the resonance condition with energetic particles. A broad plume may stop chorus from getting in, while the normal narrowing (with time) of the plume can gradually "open the gate". The group consensus was that 3D simulations with nonmonotonic density are a high priority for future progress. Simulations show that EMIC waves grow, propagate along field lines (becoming more oblique as they do), and then are damped in the ionosphere. The generation of waves makes ions more isotropic, thus relieving the anisotropy that generated the waves. Observations of a detached proton arc on 31 July 2001 were presented and compared with in situ plasma proxies for EMIC wave growth. Epoch time analysis was suggested for anything linked to plume dynamics, such as the possible link between EMIC wave growth and plume density. A simulation of EMIC waves indicates that structure within plumes (on spatial scales from meso- to fine-scale) can strongly modulate wave growth, and therefore this internal structure must be considered/included in future models. Chorus excitation by anisotropic ring current electrons was modeled, showing strong pitch angle scattering by chorus (outside) and hiss (inside) regions of cold plasma density. Motivated by in situ observations, three imperative questions were identified: (1) What are the conditions that drive waves? (2) What are the effects of these waves? (3) How do measured plasma conditions compare to linear theory? PMI Breakout 3: 13:30 - 15:30pm. Topic: (Joint with CEDAR) "M-I Coupling in the Plasmaspheric Boundary Layer". Seven (7) scheduled presentations were given in this session, by Erickson, Brandt, Zhang, Ruohoniemi, Goldstein, Chappel (INVITED), and Foster. The role of oxygen ions in SAR arc formation was discussed (mechanism: ring current heating of cold plasmaspheric ions), highlighting once again (as in previous discussions) the urgent need for better understanding and modeling of composition. The inner magnetospheric electric field was discussed at length in this session, including variability in the PBL, and general electrodynamics initiated by region-2 M-I coupling. A superposed epoch analysis of Cluster electric fields was shown to produce dynamic features of the inner magnetospheric fied, keyed to storm phase, and statistical characterization of SAPS was presented. The capabilities of the MSI/SuperDARN radars (just coming online) were discussed. It was decided that a coordinated campaign using all available midlatitude radars should be initiated in the coming years. Science and Programmatic Imperatives for the Community At the three PMI Breakout Sessions this year, the group discussions identified several urgent science and programmatic imperatives that are required to advance PMI science: * Ion Composition: Observations and models of inner magnetospheric ion composition are urgently needed to close the loop on several PMI science topics, including wave growth and wave-particle interactions, global MHD, and the possible role of oxygen enrichment in modulating dayside reconnection and substorms. * Plume Structure: Modelers need to get more meso- to fine-scale structure into their simulated plumes, in order to match the observed cross-scale structure. * UT and Longitudinal Effect: For several years various case studies have hinted that there may be a longitudinal (and/or UT) modulation of the strength of storms and the density of plumes. This effect must be quantified and understood. * Wave Growth, Propagation, and Resonance: Simulations need to use 3D, realistic density for their plasmaspheres (e.g., cross-scale spatial structure both in and out of plumes, nonmonotonic density profiles, and profiles constrained by measurements). We need to know the conditions that drive waves, and we need to know the effects of both those conditions and of the waves. We also must gauge how well measured plasma conditions agree with the linear theory that is widely used. * Epoch Time Analysis: For anything linked to plume dynamics (density, waves, etc.), a superposed epoch analysis is recommended because standard (purely indicial) statistical analysis may obscure physical processes that are initiated or terminated at particular storm phases. * Community Activities: The PMI Modeling Challenge (see below) will foster broader community involvement in PMI science, and will document the state of the art of plasmaspheric modeling. A handful of new data sources have come to the fore, and the community should act on this new availability/prominence in the next year(s): (a) Use the existing and extensions to SuperDARN MSI radar stations; (b) Conduct a coordinated campaign between MSI and Millstone Hill radars, and possibly including others (e.g., Balloon and/or TEC data); (c) Use the full TEC capabilities, i.e., full tomographic inversions and ionospheric measurements; and (d) Encourage close coordination/collaboration with the efforts of the NASA LWS TR&T /FST on the Plasmasphere, in the next year or so. PMI Modeling Challenge: 2011 – 2012. The main coordinated activity for the next year of the PMI Focus Group is to initiate and conduct the PMI Modeling Challenge. For this Challenge, two events were selected: (A) DISTURBANCE interval: 8-11 June 2001 (days 159-162). (B) QUIET interval: 2-5 February 2001 (days 33-36). Participants in the PMI Modeling Challenge will provide data and modeling/simulation results, under the guidance of Maria Spasojevic, who has agreed to lead/coordinate the effort. A full list of data and modeling-result providers can be found at http://tinyurl.com/gempmi. The results of the GEM PMI Modeling Challenge will be presented at the GEM 2012 Summer Workshop, and published in a coordinated, linked series of papers, most likely in Journal of Geophysical Research. In addition to the PMI Modeling Challenge, there are numerous ongoing studies by researchers participating in the PMI FG. Coordination of these various studies will continue to 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. ---------------------------------------------------------------------- 2. Workshop Report: Nonlinear Plasma Effects in Auroral/Subauroral Plasmas ---------------------------------------------------------------------- Conveners: Evgeny Mishin (AFRL) and Anatoly Streltsov (Dartmouth) This CEDAR/GEM workshop was held to make an assessment of the contribution of nonlinear plasma processes to the dynamics of the magnetosphere-ionosphere system with the emphasis on nonlinear interactions between electromagnetic waves and plasma at auroral and subauroral latitudes. These questions are of great interest for the CEDAR and GEM communities. Invited speakers summarized recent progress in theory, modeling, and observations of wave plasma processes at auroral and sub-auroral latitudes and discussed future directions of research. The first session was devoted to the Farley-Buneman instability in the E-region ionosphere and its implications: Meers Oppenheim at length described the striking results of the state-of-the-art 3d PIC simulations of Farley-Buneman turbulence that quantitatively explain anomalous heating of ionospheric electrons observed in numerous experiments. Jean-Pierre StMaurice, as usual brightly, overviewed a renormalized theory of the nonlinear evolution of Farley-Buneman waves and implications for the transport properties of the turbulent E region. The two presentations sparked off a lively theoretical discussion on the applicability of different nonlinear approaches to this strongly-nonlinear problem. Yakov Dimant demonstrated how important are anomalous heating and conductivity due to Farley-Buneman turbulence for magnetosphere-ionosphere coupling. In particular, accounting for these effects in a global M-I model helped to almost eliminate the discrepancy between the modeled and observed polar cap potentials. D. Hysell’s pure theoretical talk on how the known effect of saturation of the phase speed of Farley Buneman waves can be derived in terms of the stochastic approach concluded the session. Nonlinear phenomena in the topside ionosphere and magnetosphere were discussed in the second session. Nagendra Singh presented analytical and numerical results describing kinetic features of large-scale Alfvén waves in the auroral plasma. Particularly impressive were the effects of coupling of Alfvén waves and density irregularities of various scale-lengths. Anatoly Streltsov’s modeling results on coupling between the ionosphere and magnetosphere at high latitudes unambiguously demonstrated the fundamental role of nonlinear multi- scale, multi-fluid processes in formation of small-scale intense auroral phenomena. Evgeny Mishin presented a new concept of Sub- Auroral Ion Drifts (SAID) based on recent Cluster/DMSP/Polar magnetically-conjugate observations. The formation of SAID is explained in terms of short-circuiting of substorm-injected plasma jets via the plasmasphere forming a turbulent plasmaspheric boundary layer. Jhanan Tu’s presentation demonstrated a new way of thinking about different frames of references in measuring electric field in the ionosphere and calculating dissipation of the electromagnetic energy in the ionosphere on time-scales less than the Alfven transient time. Overall, the presentations have shown significant interest among CEDAR and GEM communities in conducting coherent, synchronized research of nonlinear plasma effects in the coupled MI system at auroral and subauroral latitudes. ---------------------------------------------------------------------- 3. JOB OPENING: 3 Post-doc Positions at IRAP, Toulouse, France ---------------------------------------------------------------------- The Centre de Données de la Physique des Plasmas (CDPP) at the Institut de Recherche en Astrophysique et Planétologie (IRAP) in Toulouse (France) is opening three post-doc positions in the following themes of research: 1 - Heliospheric research (solar wind and/or Earth's magnetosphere) Contact: Benoit Lavraud (Benoit.Lavraud@irap.omp.eu) and Christian Jacquey (Christian.Jacquey@irap.omp.eu) 2 - Planetary plasma physics (planetary magnetospheres, moon- magnetosphere interactions) Contact: Nicolas André (Nicolas.Andre@irap.omp.eu) and Christian Jacquey (Christian.Jacquey@irap.omp.eu) 3 - Heliosphere and planetology (Sun-planets connection) Contact: Vincent Génot (Vincent.Genot@irap.omp.eu) and Christian Jacquey (Christian.Jacquey@irap.omp.eu) The candidates will conduct their research activities at IRAP and will actively contribute to the design and testing of the science analysis tools developed by CDPP (e.g., AMDA: an Automated Multi-Dataset Analysis web-based tool at cdpp-amda.cesr.fr/). Candidates should have obtained their PhD and have worked on areas related to the aforementioned themes. Each post-doc position is nominally for 1 year with possibilities for extension. Net salary is about 2000 euros per month or more depending on experience. Start date for the positions is intended as soon as possible. Interested candidates should send a cover letter and their CV to the contact point given above. +-------------------------------------------------------------------+ | 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 | +-------------------------------------------------------------------+