HR: 09:15h
AN: SM51D-06    [Abstracts]
TI: Radial Diffusion as a Potential Source and Loss Mechanism of Relativistic Electrons in the Outer Radiation Belt
AU: * Shprits, Y Y
EM: yshprits@atmos.ucla.edu
AF: UCLA, University of California, Los Angeles Department of Atmospheric and Oceanic Sciences, 405 Hilgard Ave Box 951565 , Los Angeles, CA 90095 United States
AU: * Shprits, Y Y
EM: yshprits@atmos.ucla.edu
AF: LANL, NIS-1, Mail Stop D-466 Los Alamos National Laboratory Los Alamos , Los Alamos, NM 87545 United States
AU: Thorne, R
EM: rmt@atmos.ucla.edu
AF: UCLA, University of California, Los Angeles Department of Atmospheric and Oceanic Sciences, 405 Hilgard Ave Box 951565 , Los Angeles, CA 90095 United States
AU: Friedel, R
EM: friedel@nis.lanl.gov
AF: LANL, NIS-1, Mail Stop D-466 Los Alamos National Laboratory Los Alamos , Los Alamos, NM 87545 United States
AU: Reeves, G D
EM: reeves@lanl.gov
AF: LANL, NIS-1, Mail Stop D-466 Los Alamos National Laboratory Los Alamos , Los Alamos, NM 87545 United States
AU: Fennel, J F
EM: Joseph.F.Fennell@aero.org
AF: Aerospace Corp., Mail Stop M2-259 The Aerospace Corp. P.O. Box , El Segundo, CA 92957 United States
AU: Baker, D
EM: Daniel.Baker@lasp.colorado.edu
AF: LASP, Laboratory for Atmospheric and Space Physics, University of Colorado 1234 Innovation Drive, Boulder, Colorado 80303-7814, USA , Boulder, CO 80303-7814 United States
AU: Shrikanth, K
EM: Shrikanth@lasp.colorado.edu
AF: LASP, Laboratory for Atmospheric and Space Physics, University of Colorado 1234 Innovation Drive, Boulder, Colorado 80303-7814, USA , Boulder, CO 80303-7814 United States
AU: Horne, R
EM: r.horne@bas.ac.uk
AF: BAS, British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, , Cambridge, CB3 0ET United Kingdom
AB: The loss mechanisms responsible for the sudden depletions of the outer electron radiation belt are examined based on observations and radial diffusion modeling. SAMPEX data for October-December 2003, indicates that depletions are correlated with increases in geomagnetic activity and also correlated with sudden increases in the solar wind dynamic pressure. Multi-channel HEO observations show that depletions are seen at energies as low as a few hundred keV. For the same events high energy proton channels also show decrease in fluxes at higher L-values. These observations are consistent with outward radial diffusion driven by the loss to magnetopause. We further examine the viability of the outward radial diffusion loss by comparing CRRES observations with a radial diffusion model simulations. Model-data comparison shows that flux variation near geosynchronous orbit can be effectively propagated by the outward radial diffusion to lower L-values and can account for the main phase storm depletions. The presence of the outward radial diffusion rises an important question: What is the origin of the relativistic electrons at geosynchronous orbit plasma sheet or radiation belts?
DE: 2720 Energetic particles: trapped
DE: 2730 Magnetosphere: inner
DE: 2753 Numerical modeling
DE: 2774 Radiation belts
DE: 2788 Magnetic storms and substorms (7954)
SC: SPA-Magnetospheric Physics [SM]
MN: Fall Meeting 2005