HR: 1330h
AN: SH42A-0483    [PDF]
TI: Dynamic Modeling of Solar Energetic Particle Cutoffs During Geomagnetic Storms
AU: * Kress, B T
EM: bkress@northstar.dartmouth.edu
AF: Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Laboratory, Hanover, NH 03755 United States
AU: Hudson, M K
EM: maryk@gaia.dartmouth.edu
AF: Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Laboratory, Hanover, NH 03755 United States
AU: Perry, K L
EM: Kara_L._Perry@Mac
AF: Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Laboratory, Hanover, NH 03755 United States
AB: We investigate numerically the relationship between time variations in the geomagnetic cutoff and prompt trapping of Solar Energetic Particles inside the pre-storm cutoff, which form new radiation belt populations distinct from the CRAND-produced inner zone. This is done for several CME-shock initiated geomagnetic storms including the 14 July 2000, 24 Nov 2001, and 21-23 April 2002 storms. Following Smart and Shea [2000], Solar Energetic Particle (SEP) access is determined by computing the reverse particle trajectories. Magnetospheric fields are obtained from the Lyon-Feder-Mobarry (LFM) global MHD model, which is driven by measured solar wind parameters at the sunward boundary. We find well-defined surfaces of constant cutoff that exhibit dynamic behavior in response to solar wind conditions. The results suggest that an enhanced solar wind dynamic pressure plays a direct role in the observed ion injections. Additional mechanisms for SEP access and trapping are considered, including the the role of ULF waves.
DE: 2118 Energetic particles, solar
DE: 2784 Solar wind/magnetosphere interactions
SC: SPA - Solar and Heliospheric Physics [SH]
MN: 2003 Fall Meeting