HR: 17:20h
AN: SM24A-05 INVITED     [Abstracts]
TI: The role of the plasmapause and plasma plumes in EMIC wave source location and propagation
AU: * Fraser, B J
EM: brian.fraser@newcastle.edu.au
AF: Centre for Space Physics, University of Newcastle, University Drive , Callaghan, NSW 2308, Australia
AU: Singer, H J
EM: howard.singer@noaa.gov
AF: NOAA/SEC, 325 Broadway, Boulder, CO 80305, United States
AU: Moldwin, M B
EM: mmoldwin@igpp.ucla.edu
AF: Department of Earth and Space Sciences University of California, 595 Charles Young Drive East, Box 951567, Los Angeles, CA 90095-1567, United States
AU: Goldstein, J
EM: jGoldstein@swri.org
AF: Space Science and Engineering Division, Southwest Research Institute, 9503 Commerce St, San Antonio, Tex 78227, United States
AU: Thomsen, M F
EM: m.thomsen@lanl.gov
AF: Space and Atmospheric Science Group, Los Alamos National Laboratory, Bikini Atoll Rd., SM 30 , Los Alamos, NM 87545, United States
AB: It has generally been assumed in the past that the steep density gradient in the radial density profile of the magnetospheric plasma, the plasmapause, is the favoured region for the generation and propagation of electromagnetic ion cyclotron (EMIC) waves. This is the region of overlap between the expanding cold plasmasphere with the inner edge of the hot ring current during storm recovery, providing favourable conditions for EMIC instability. The plasmapause is also expected to provide a convenient gradient for guiding waves from equatorial sources to higher latitudes. Although EMIC waves are seen at the plasmapause, they have been seen more frequently by AMPTE and CRRES outside the plasmapause. More recently extended radial plasma plumes, attached to the plasmasphere have been seen in IMAGE-EUV data. These provide enhanced radial plasma density and associated azimuthal gradients. Using CRRES, GOES, LANL and IMAGE-EUV data the role of plasma gradients in determining EMIC source location and propagation properties will be considered using case studies and statistics. These results will provide an indication of the conditions under which EMIC waves generation occurs in the magnetosphere, and consequently their role in ring current ion loss.
DE: 2730 Magnetosphere: inner
DE: 2768 Plasmasphere
DE: 2772 Plasma waves and instabilities (2471)
DE: 2778 Ring current
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Joint Assembly