HR: 12:05h
AN: SM12A-08    [Abstracts]
TI: A dynamic model of the radiation-belt electron phase-space density based on POLAR/HIST measurements
AU: * Vassiliadis, D
EM: dimitris.vassiliadis@sarissatech.com
AF: Sarissa Technologies, P.O. Box 10325, Rockville, MD 20849-0325,
AU: Green, J C
EM: janet.green@noaa.gov
AF: NOAA/SEC, 325 Broadway, Boulder, CO 80305,
AB: The response of the energetic-electron phase-space density (PSD) in the radiation belts is subject to a delicate combination of acceleration and loss processes which are strongly determined by the magnetospheric configuration and field disturbance level. We quantify the response of the density to stormtime fields as observed by the HIST detector on board POLAR. Several distinct modes are identified, characterized by peak second- and third- adiabatic invariants and peak delay time. The modes represent quasiadiabatic transport due to ring current activity; high L* (~6), day-long acceleration linked to ULF wave-particle interaction; and low-L* (~3), minute- to hour-long acceleration interpreted to be due to transient inductive fields or VLF wave-particle interaction. The net transport due to these responses is not always or everywhere diffusive, therefore we quantify the degree of departure from diffusive transport for specific storm intervals and radial ranges. Taken together the response modes comprise a dynamic, nonlinear model which allows us to better understand the historic variability of the high-energy tail of the electron distribution in the inner magnetosphere.
DE: 2720 Energetic particles: trapped
DE: 2774 Radiation belts
DE: 2788 Magnetic storms and substorms (7954)
DE: 7984 Space radiation environment
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Fall Meeting