HR: 08:30h
AN: SM31A-01 INVITED     [Abstracts]
TI: Plasmaspheric Influence on Radiation Belts During Major Geomagnetic Storms
AU: * Goldstein, J
EM: jgoldstein@swri.edu
AF: Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78238 United States
AU: Baker, D
EM: daniel.baker@lasp.colorado.edu
AF: University of Colorado Boulder, LASP 1234 Innovation Drive, Boulder, CO
AU: Sandel, B R
EM: sandel@arizona.edu
AF: University of Arizona, Lunar and Planetary Laboratory, Tucscon, AZ
AU: Burch, J L
EM: jburch@swri.edu
AF: University of Arizona, Lunar and Planetary Laboratory, Tucscon, AZ
AU: Fennell, J F
EM: joseph.fennell@aero.org
AF: Aerospace Corporation, MS M2-259, Los Angeles, CA
AB: We investigate a possible causal relationship between erosion of the plasmasphere and enhancement of the radiation belts during major geomagnetic storms. The Earth's plasmasphere was observed by the IMAGE EUV imager to be drastically reduced in size by the 2003 Halloween geomagnetic storm event. Before the storm the plasmapause was seen at roughly 4 Earth radii (RE) geocentric distance; after the storm, the plasmapause had moved inside 2 RE. This dramatic erosion of the plasmasphere apparently had a profound effect on the global distribution of the Van Allen radiation belts. Wave-particle interactions inside the plasmasphere normally act to remove the radiation belt electrons inside the slot region; however, in the days following the 2003 Halloween storm's drastic plasmasphere erosion, SAMPEX witnessed the formation of an extremely intense new radiation belt in what was formerly the slot region. This chain of events suggests that the plasmasphere configuration can have a primary influence on the global radiation belt distribution. We present preliminary results of the investigation of this possible relationship for three major geomagnetic storms, using global images of the plasmasphere side-by-side with in situ energetic particle data. We discuss likely mechanisms for quickly accelerating electrons to the high levels observed in the slot that normally is devoid of such relativistic electrons.
DE: 2716 Energetic particles, precipitating
DE: 2720 Energetic particles, trapped
DE: 2722 Forecasting
DE: 2730 Magnetosphere--inner
DE: 2768 Plasmasphere
SC: SPA-Magnetospheric Physics [SM]
MN: 2005 Joint Assembly