HR: 0800h
AN: SM31B-1236    [Abstracts]
TI: Solar wind and IMF control of substorm onset
AU: * Weygand, J M
EM: jweygand@igpp.ucla.edu
AF: Institute of Geophysics and Planetary Physics, University of California, Los Angeles, Los Angeles, CA 90095-1567 United States
AU: McPherron, R L
EM: rmcpherron@igpp.ucla.edu
AF: Institute of Geophysics and Planetary Physics, University of California, Los Angeles, Los Angeles, CA 90095-1567 United States
AU: Liou, K
EM: Kan.Liou@jhuapl.edu
AF: Applied Physics Laboratory, The Johns Hopkins University, Laurel, MD 20723-6099 United States
AU: Frey, H
EM: hfrey@ssl.berkeley.edu
AF: Space Sciences Laboratory, University of California, Berkeley, Berkeley, CA 94720-7450
AB: Few studies of solar wind control of substorm onset exist and only two have good statistics using the IMF. Those studies with solar wind statistics employ only a few 10's of events, yet it has been proposed that solar wind dynamic pressure changes may trigger substorms. While a small percentage of substorms are believed to be triggered by solar wind dynamic pressure variations and hence, solar wind control of the substorms is not surprising, a significant number of substorm events exist that appear to have either IMF triggers or no triggers at all. We will show the results of a statistical examination of solar wind control of substorm onset using propagated solar wind data. Furthermore, we will demonstrate the difference in the solar wind control of the substorm onset for triggered and non-triggered substorms. This type of study is important for both space weather predictions of substorm onset and for use in substorm modeling. Moreover, the results of this study will be of interest to the upcoming THEMIS mission.
UR: http://www.igpp.ucla.edu/jweygand
DE: 2164 Solar wind plasma
DE: 2784 Solar wind/magnetosphere interactions
DE: 2788 Storms and substorms
SC: SPA-Magnetospheric Physics [SM]
MN: 2004 AGU Fall Meeting