HR: 0800h
AN: SH31A-1156 [Abstracts]
TI: Elemental Abundance Variations of Gradual SEP Events at Low Energies as Measured by ACE/ULEIS and
WIND/STEP Over the Last Solar Cycle
AU: * Al-Dayeh, M
EM: maldayeh@fit.edu
AF: Department of Physics and Space Sciences, Florida Institute of Technology, 150 W University Blvd.,
Melbourne, FL 32901
United States
AU: Dwyer, J R
EM: jdwyer@fit.edu
AF: Department of Physics and Space Sciences, Florida Institute of Technology, 150 W University Blvd.,
Melbourne, FL 32901
United States
AU: Rassoul, H K
EM: rassoul@fit.edu
AF: Department of Physics and Space Sciences, Florida Institute of Technology, 150 W University Blvd.,
Melbourne, FL 32901
United States
AU: Mason, G M
EM: Glenn.Mason@umail.umd.edu
AF: Department of Physics, University of Maryland, College Park, MD 20742
United States
AU: Desai, M I
EM: desai@uleis.umd.edu
AF: Department of Physics, University of Maryland, College Park, MD 20742
United States
AU: Mazur, J E
EM: Joseph.E.Mazur@aero.org
AF: Aerospace Corporation, 2350 E. El Segundo Blvd., El Segundo, CA 90245-4651
United States
AB:
Solar energetic particles (SEPs) provide a measuring technique to probe the composition of the solar corona independent of
spectroscopic measurements. However, SEP elemental abundances in large gradual events can vary considerably from event to
event, exceeding one order of magnitude in some cases; this must be taken into account when using SEP measurements to deduce
the coronal composition. The causes of these variations are unfortunately still not clear, and may be produced either by
acceleration/transport effects or variations in the source abundances. Using the Ultra-Low-Energy-Isotope-Spectrometer
(ULEIS) onboard the Advanced Composition Explorer (ACE) and the Supra-Thermal-through-Energetic-Particle (STEP) instruments
onboard the WIND spacecraft, we have measured the fluxes of Fe and the C-N-O at energies between 0.02 and 0.6 MeV/nucleon and
extracted the C to O ratios for a survey of gradual SEP events between 1995 and 2003. In this presentation, we will report
on preliminary results of this study.
DE: 7514 Energetic particles (2114)
DE: 7536 Solar activity cycle (2162)
DE: 2114 Energetic particles, heliospheric (7514)
DE: 2118 Energetic particles, solar
DE: 2162 Solar cycle variations (7536)
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2004 AGU Fall Meeting