HR: 0800h
AN: SH21A-0295    [Abstracts]
TI: Solar Wind Short Distance Propagation Model With Moving Boundaries
AU: * Kulchitsky, A
EM: kulchits@arsc.edu
AF: University of Alaska Fairbanks, ARSC, PO Box 756020, Fairbanks, AK 99775-6020, United States
AB: Parameters of the Interplanetary Magnetic Field (IMF) and solar wind are important factors that affect Earth's magnetosphere. Measurements of the IMF taken at the first Lagrange point (L₁) by the ACE space satellite, about 230 Earth Radii away, are typically used for estimation of IMF near the Earth. In many geophysical applications, it is assumed that we can use a simple kinematic approach to map the parameters measured at the satellite to the Earth by shifting them in time by a "time delay". This time delay is calculated using solar wind velocity and the distance from the satellite to the Earth. However, this approach can lead to incorrect IMF estimation near the Earth. The kinematic approach does not take into account that IMF can be tilted with respect to the solar wind propagation direction and therefore the parameters have different time delays. Particles also interact during their way from ACE satellite to magnetosphere, which can introduce additional errors. Our model takes into account both factors. A simplified 1D solar wind propagation model was derived for this case using mass and momentum conservation laws and Maxwell's equations. The model is simple and fast enough to use even in real-time applications, yet it takes into account real conservation laws of solar wind motion. The previous model of IMF and the solar wind near Earth magnetosphere we developed was improved recently by making domain boundaries move with the satellite and by taking into account both ACE satellite and Earth's speed. The new model also takes into account the IMF's inclination with respect to the solar wind propagation vector. We validated our new models on different measurements obtained from the ACE and WIND satellites. Comparisons of these measurements and calculations shows an improvement of IMF calculations compared to the simple kinematic delay method and our previous model.
DE: 0654 Plasmas
DE: 2134 Interplanetary magnetic fields
DE: 2164 Solar wind plasma
DE: 7959 Models
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Fall Meeting