HR: 0800h
AN: SM21A-0326    [Abstracts]
TI: Properties and Possible Causes of Low Latitude Broadband Accelerated Electron Events During Large Storms From FAST and Altitude Dependence of PSBL Alfven Waves From Polar
AU: * Dombeck, J
EM: johnd@fields.space.umn.edu
AF: School of Physics and Astronomy, Univ. of Minnesota, 116 Church St. SE, Minneapolis, MN 55455, United States
AU: Cattell, C
EM: cattell@fields.space.umn.edu
AF: School of Physics and Astronomy, Univ. of Minnesota, 116 Church St. SE, Minneapolis, MN 55455, United States
AU: Wygant, J
EM: jwygant@fields.space.umn.edu
AF: School of Physics and Astronomy, Univ. of Minnesota, 116 Church St. SE, Minneapolis, MN 55455, United States
AU: McFadden, J
EM: mcfadden@ssl.berkeley.edu
AF: Space Sciences Laboratory, Univ. of California at Berkeley, 7 Gauss Way, Berkeley, CA 94720, United States
AU: Keiling, A
EM: keiling@ssl.berkeley.edu
AF: Space Sciences Laboratory, Univ. of California at Berkeley, 7 Gauss Way, Berkeley, CA 94720, United States
AU: Strangeway, R
EM: strange@igpp.ucla.edu
AF: Institute of Geophysics and Planetary Physics, Univ. of California at Los Angeles, 405 Hilgard Ave., Los Angeles, CA 90095, United States
AB: A variety of phenomena which occur during large geomagnetic storms (DST<-75 nT) are not yet fully understood. One such phenomenon, which affects ionospheric conditions and may be useful as a diagnostic for processes occurring at ~3-6 Re, is the occurrence of low latitude (ILat<65) broadband accelerated electron events observable at altitudes of ~2000-4000 km by the FAST satellite. Results of an initial study of 3+ years of FAST data indicate that such electrons are observed in ~6% of the low latitude, nightside (21- 03 MLT) FAST data during large storms versus <~1% during non-storm times. Individual storms have observed occurrence probabilities as high as 24%. Although properties of the events, and thus likely causes, vary, many events are accompanied by particle distributions and wave signatures that are similar to those observed during Alfvén-wave accelerated electron events on the plasma sheet boundary layer (PSBL). Alfvén- wave acceleration of electrons on the PSBL has been and continues to be well studied. Results of a recent study of PSBL Alfvén-wave events observed with Polar that may provide additional insight will also be discussed. That study compares altitude dependencies of wave properties at ~3-9 Re and differences in these dependencies between major storm and non-storm events.
DE: 2716 Energetic particles: precipitating
DE: 2730 Magnetosphere: inner
DE: 2736 Magnetosphere/ionosphere interactions (2431)
DE: 2788 Magnetic storms and substorms (7954)
DE: 7954 Magnetic storms (2788)
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Fall Meeting