HR: 0800h
AN: SM51B-1305 [Abstracts]
TI: Effect of Magnetic Clouds and IP Shocks on AL and Dst Indices
AU: * Mays, M L
EM: lmays@physics.utexas.edu
AF: Institute for Fusion Studies, The University of Texas at Austin, 1 University station, C1500, Austin,
TX 78712
United States
AU: Pratt, J
EM: jpratt@physics.utexas.edu
AF: Institute for Fusion Studies, The University of Texas at Austin, 1 University station, C1500, Austin,
TX 78712
United States
AU: Spencer, E
EM: espencer@sunfire1.ece.utexas.edu
AF: Institute for Fusion Studies, The University of Texas at Austin, 1 University station, C1500, Austin,
TX 78712
United States
AU: Horton, W
EM: horton@physics.utexas.edu
AF: Institute for Fusion Studies, The University of Texas at Austin, 1 University station, C1500, Austin,
TX 78712
United States
AU: Doxas, I
EM: Isidoros.Doxas@colorado.edu
AF: Center for Integrated Plasma Studies, University of Colorado, Boulder, CO 80309
United States
AB:
We construct analytic solar wind signals using data from ACE for the
Wang et al. Oct. 3-6 2000 event in which a fast forward shock advanced
into a preceding magnetic cloud. We examine the response of the WINDMI model, an eight
dimensional model of the solar wind driven magnetosphere-ionosphere
system, to our analytic signals
for this event. The auroral magnetometer AL signal result from the
model driven by the analytic solar wind dynamo voltage captures
the 8 substorms in the main phase of the storm. The model
mid-latitude magnetometer Dst signal used to quantify
magnetospheric storms has the correct qualitative feature of a sharp
rise for the expansion phase and a slower decay for the recovery phase. The role of the shock can be
examined by using analytic signals in which the shock feature in the density,
solar wind velocity, and magnetic field are tested individually. The
shock near the end of the 42 hr magnetic cloud is shown to
be largely responsible for the very large region 1 field aligned current surges
associated with the -AL > 1300 nT peaks at the end of the main
phase of the storm.
The work is supported by NSF-ATM grant 0229863.
DE: 2778 Ring current
DE: 2784 Solar wind/magnetosphere interactions
DE: 2788 Magnetic storms and substorms (7954)
SC: SPA-Magnetospheric Physics [SM]
MN: Fall Meeting 2005