HR: 10:20h
AN: SM22A-01    [Abstracts]
TI: Solar wind ion access to the plasma sheet during the September 24-25, 1998 magnetic storm
AU: * Peroomian, V
EM: vahe@igpp.ucla.edu
AF: UCLA-IGPP, Box 951567, Los Angeles, CA 90095-1567 United States
AU: El-Alaoui, M
EM: mostafa@igpp.ucla.edu
AF: UCLA-IGPP, Box 951567, Los Angeles, CA 90095-1567 United States
AU: Ashour-Abdalla, M
EM: mabdalla@igpp.ucla.edu
AF: UCLA-IGPP, Box 951567, Los Angeles, CA 90095-1567 United States
AU: Zelenyi, L M
EM: lzelenyi@iki.rssi.ru
AF: Space Research Institute, 84/32 Profsoyuznaya, Moscow, 117997 Russian Federation
AB: We have used a global time-dependent magnetohydrodynamic (MHD) simulation of the magnetosphere and particle tracing calculations to determine the entry of solar wind ions into the magnetosphere and their access to the storm-time near-Earth plasma sheet and ring current during the September 24-25, 1998 magnetic storm. The September 24 - 25, 1998 magnetic storm began with the arrival of a sudden impulse at 23:45 UT on September 24th which abruptly increased the solar wind dynamic pressure on the nose of the magnetosphere from 2 nPa to 15 nPa. Dst reached a minimum of -207 at 1000 UT on September 25th. To study solar wind entry, we launched ions upstream of the bowshock at 5-minute intervals beginning one hour prior to the shock arrival and continuing throughout the sudden storm commencement and the main phase of the storm. Ions were launched with the solar wind streaming velocity and thermal spread measured at that time. Following the particle trajectories through detectors placed within the magnetopause current layer allowed us to gain a better understanding of the transport and acceleration of solar wind plasma through the magnetopause during this storm. We will also show time-varying maps of the solar wind ion density in the plasma sheet and ring current during the storm, the energization of ions in the magnetotail current sheet, and their loss from the magnetosphere.
DE: 2724 Magnetopause and boundary layers
DE: 2744 Magnetotail
DE: 2764 Plasma sheet
DE: 2778 Ring current
DE: 2788 Magnetic storms and substorms (7954)
SC: SPA-Magnetospheric Physics [SM]
MN: Fall Meeting 2005