HR: 0800h
AN: SM41A-1108    [Abstracts]
TI: Solar Energetic Particle Entry and Trapping in the Magnetosphere During Geomagnetic Storms
AU: * Kress, B T
EM: bkress@northstar.dartmouth.edu
AF: Department of Physics and Astronomy, Dartmouth College, Wilder Lab HB 6127, Hanover, NH 03755 United States
AU: Hudson, M K
EM: maryk@gaia.dartmouth.edu
AF: Department of Physics and Astronomy, Dartmouth College, Wilder Lab HB 6127, Hanover, NH 03755 United States
AU: Slocum, P L
EM: Penny.L.Slocum@aero.org
AF: Space Science Applications Laboratory, The Arospace Corporation, PO Box 92957, Los Angeles, CA 90009 United States
AB: We investigate numerically the relationship between geomagnetic cutoff and the prompt trapping of Solar Energetic Particles (SEPs) in the inner magnetosphere during storms, which form new radiation belt populations distinct from the cosmic ray albedo neutron decay (CRAND) source protons in the inner zone. SEP cutoffs are modeled using the Lyon-Feder-Mobarry (LFM) global magnetosphere MHD code, which is driven by measured solar wind parameters at the sunward boundary. In a follow up to our recent paper [Kress et al., 2004], we further study SEP trajectories in fields from the 24 NOV 2001 LFM storm simulation. By mapping surfaces of constant cutoff rigidity in the LFM fields, we show that SEPs with access to the innermost L shells enter through the magnetopause on the day side and predominately in the magnetic equatorial plane. It is found that a significantly compressed magnetopause has a profound effect on the asymmetry of the cutoff surface suggesting a mechanism for SEP trapping.
DE: 2720 Energetic particles, trapped
DE: 2740 Magnetospheric configuration and dynamics
DE: 2753 Numerical modeling
DE: 2788 Storms and substorms
SC: SPA-Magnetospheric Physics [SM]
MN: 2004 AGU Fall Meeting