HR: 1340h
AN: SM33B-1345    [Abstracts]
TI: Investigation of Magnetic Storms Impact on the Magnetosphere's Morphology and its Current System by Global Hybrid Models
AU: * Kazeminezhad, F
EM: fkazeminezhad@wvhtf.org
AF: West Virgina High Tech Consortium Foundation, 1000 Technology Drive, Suite 1000., Fairmont, Wv 26554, United States
AB: \begin{document} Two and three dimensional hybrid models of massless fluid electrons and kinetic ions are utilized to investigate the impacts of interplanetary shocks presumably resulting from magnetic storms on the magnetosphere. The codes are structured to model the magnetosphere dynamics of the Earth-Solar wind system by utilizing finite element mesh systems specifically tailored to magnetosphere's regions. The 2.5d spans many hundred Earth radii in each direction (upstream, downstream, dawn and dusk); the 3d finite element code which is recently developed focuses primarily on the inner magnetosphere. Realistic parameters characteristic of solar wind, its IMF and geomagnetic field are used. The codes have been tested by their ability to predicting a magnetosphere by initializing a dipole at equilibrium with a flow subjected to an incoming solar wind with an IMF. The tests revealed generation of a steady state bow shock, as well as dayside reconnection (for southward IMF) as well as a tail sheet formation. The interplanetary shock is generated by a sudden enhancement of the incoming IMF by an order of magnitude. This act introduced a fast MHD shock which propagated downstream and collided with the bow shock. This collision resulted not only in a steep rise in density and temperature of the bow shock, but also in the tail sheet region as the shock propagated downstream. The densities and temperatures, though, eventually relaxed to what are normal bow shock and tail values as the fast shock left the simulation domain. The equatorial plane current system initially axisymmetric experienced a sharp increase coupled with broken symmetry upon the storm's passage. The latter results are consistent with recent results reported by Tsyganenko and Sitnov (JGR, Vol. 112, A06225, 2007). The ion velocity flow fields also demonstrated features consistent with the equatorial current system primarily on the dayside. These investigations are aimed at better understanding of the transport of energy and momentum by geomagnetic storms into the inner magnetosphere by kinetic processes as well as validating the presumed structure of the inner magnetosphere's ring current system. This work is supported by the NSF-ATM-0651690. \end{document}
DE: 2700 MAGNETOSPHERIC PHYSICS (6939)
DE: 2753 Numerical modeling
DE: 2778 Ring current
DE: 2780 Solar wind interactions with unmagnetized bodies
DE: 2788 Magnetic storms and substorms (7954)
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Fall Meeting