HR: 1330h
AN: SM22B-0238    [PDF]
TI: A Simulation Study of the Response of the Jovian Magnetosphere to Changes in the Solar Wind Dynamic Pressure and Interplanetary Magnetic Field
AU: * Walker, R J
EM: rwalker@igpp.ucla.edu
AF: Institute of Geophsics and Planetary Physics and Department of Earth and Space Science, University of California, Los Angeles, Los Angeles, CA 90095-1567 United States
AU: Ogino, T
EM: ogino@stelab.nagoya-u.ac.jp
AF: Solar Terrestrial Environment Laboratory, Nagoya University 3-13 Honohara, Toyokawa, 442-8507 Japan
AU: Fukazawa, K
EM: fukazawa@stelab.nagoya-u.ac.jp
AF: Solar Terrestrial Environment Laboratory, Nagoya University 3-13 Honohara, Toyokawa, 442-8507 Japan
AB: A rapidly rotating equatorial current sheet and plasma sheet dominates the Jovian magnetosphere. We have used a global magnetohydrodynamic (MHD) simulation to investigate the effects of changes in the solar wind dynamic pressure and interplanetary magnetic field (IMF) on the Jovian magnetospheric configuration with emphasis on changes in the equatorial plasma sheet. We have carried out three numerical experiments: 1. We set the IMF to zero and reduced the solar wind dynamic pressure from 0.09nPa to 0.011nPa in three steps. The bow shock and magnetopause moved away from Jupiter. In the middle magnetosphere near Jupiter the azimuthal velocity increased at all local times with the largest increases in the late afternoon and evening. The radial flow component in the plasma sheet was away from Jupiter in the evening and morning but toward Jupiter in the afternoon. 2. We fixed the solar wind dynamic pressure at 0.011nPa and introduced a northward IMF of 0.105nT into the solar wind. Dayside reconnection started dawnward of noon and was accompanied by duskward propagating oscillations on the magnetopause. The magnetic field and plasma pressure were anticorrelated in the waves suggesting a slow mode structure. The wave generation persisted throughout the 112 hours of the numerical experiment. The dayside reconnection was followed by reconnection in the Jovian magnetotail. Although the IMF was constant the tail reconnection was episodic with 25 to 35 hours between the reconnection intervals. The equatorial plasma sheet and flow pattern were greatly altered by the reconnection especially in the afternoon region of Jupiterward flows. 3. We fixed the solar wind dynamic pressure at 0.011nPa and introduced a southward IMF into the solar wind. For southward IMF reconnection occurred at high latitudes in the polar cusp and the bow shock and magnetopause moved away from Jupiter. The equatorial plasma sheet and flows became more axisymmetric.
DE: 2740 Magnetospheric configuration and dynamics
DE: 2753 Numerical modeling
DE: 2756 Planetary magnetospheres (5443, 5737, 6030)
DE: 6220 Jupiter
SC: SPA - Magnetospheric Physics [SM]
MN: 2003 Fall Meeting