HR: 0800h
AN: SA21A-0284    [Abstracts]
TI: Study of Proton cutoffs during geomagnetically disturbed times
AU: * Kanekal, S G
EM: shrikanth.kanekal@lasp.colorado.edu
AF: LASP, University of Colorado, 1234 Innovation Drive, Boulder, CO 80303 United States
AU: Looper, M D
EM: mark.looper@aero.org
AF: Aerospace Corporation, PO BOX 92957, Los Angeles, CA 90009 United States
AU: Baker, D N
EM: daniel.baker@lasp.colorado.edu
AF: LASP, University of Colorado, 1234 Innovation Drive, Boulder, CO 80303 United States
AU: Blake, J B
EM: Jbernard.blake@aero.org
AF: Aerospace Corporation, PO BOX 92957, Los Angeles, CA 90009 United States
AB: It is currently believed that solar energetic particles (SEP) may be accelerated at solar flares and/or at interplanetary shocks driven by coronal mass ejections (CMEs). CMEs also cause intense geomagnetic storms during which the geomagnetic field can be highly distorted.SEP fluxes penetrate the terrestrial magnetosphere and reach specific regions depending upon the geomagnetic field configuration. The cutoff latitude is a well defined latitude below which a charged particle of a given rigidity (momentum per unit charge) arriving from a given direction cannot penetrate. SEP cutoff location can therefore be potentially useful in determining the geomagnetic field configuration. This paper reports on the measurements of solar energetic proton cutoffs made by two satellites, SAMPEX and Polar during geomagnetically disturbed times. We study select SEP events and compare our measurements with cutoffs calculated by a charged particle tracing code which utilizes several currently used models of the geomagnetic field. The measured SEP proton cutoffs cover a wide range of rigidities and are obtained at high-altitudes by the HIST detector onboard Polar and at low-altitudes by the PET detctor onboard SAMPEX.
DE: 2114 Energetic particles (7514)
DE: 2716 Energetic particles: precipitating
SC: SPA-Aeronomy [SA]
MN: Fall Meeting 2005