Physics
Scientific paper
Dec 2002
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2002agufmsm11c0451f&link_type=abstract
American Geophysical Union, Fall Meeting 2002, abstract #SM11C-0451
Physics
2708 Current Systems (2409), 2736 Magnetosphere/Ionosphere Interactions, 2753 Numerical Modeling, 2760 Plasma Convection, 2784 Solar Wind/Magnetosphere Interactions
Scientific paper
The geomagnetic sudden commencement (SC) is studied numerically based on a model of buffeting the magnetosphere by the solar wind pressure impulse. The SC has the preliminary impulse (PI) phase and the main impulse (MI) phase according to behavior of plasma convection in the magnetosphere and that in the ionosphere. The magnetospheric current line in the PI event consists of the enhanced Chapman-Ferraro current in the magnetopause, the radial current along the wavefront of the compressional signal launched by the impulse, and the field-aligned current via mode coupling due to plasma non-uniformity. The PI current system is strongly affected by the magnetosphere structure. J*E is negative along the Chapman-Ferraro current in the magnetopause, which means the current generator is located there. Whereas, J*E is positive in the wavefront region of the compressional signal, which means the electromagnetic force moves plasmas. The current in the wavefront region belongs to the inertia current associated with rapid variation due to sudden compression of the magnetosphere. We present a quantitative model of the PI model presented by Araki [1994] by using our numerical simulation. In the PI phase, the magnetospheric vortex is not invoked. The ionosphere does not affect the plasma behavior in the magnetosphere. In the transition from the PI phase to the MI phase, there appears the ionospheric FAC with the region 1 sense (reversed sense of the FAC in the PI phase). At the same time, the new sunward flow appears in the magnetosphere and produces flow shear. This flow shear invokes the FAC. The current generator is located in the inner magnetosphere. In the MI phase, the current is generated due to compression of the nightside magnetopause. The current generated there flows into the ionosphere as the FAC with the region 1 sense. This current is associated with the magnetospheric plasma convection in the closed field line. In this case, the plasma convection is not produced by magnetic reconnection in the magnetopause.
Fujimoto Kazuya
Fujita Shigeo
Kikuchi Tatsuru
Tanaka Toshiaki
No associations
LandOfFree
A Numerical Simulation of the Geomagnetic Sudden Impulse does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with A Numerical Simulation of the Geomagnetic Sudden Impulse, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A Numerical Simulation of the Geomagnetic Sudden Impulse will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1438185