HR: 0800h
AN: SH51B-0274    [Abstracts]
TI: Structure of the Moon's Wake-Tail under different IMF conditions: Hybrid simulations
AU: * Travnicek, P
EM: trav@alenka.ufa.cas.cz
AF: Institute of Atmospheric Physics, The Academy of Sciences of the Czech Republic, Bocni II/1401, Prague 4, 14131 Czech Republic
AU: Hellinger, P
EM: Petr.Hellinger@ufa.cas.cz
AF: Institute of Atmospheric Physics, The Academy of Sciences of the Czech Republic, Bocni II/1401, Prague 4, 14131 Czech Republic
AU: Schriver, D
EM: dave@igpp.ucla.edu
AF: Institute of Geophysics and Planetary Physics, University of California, Los Angeles, Los Angeles, CA 90095-1567 United States
AU: Ashour-Abdalla, M
EM: mabdalla@igpp.ucla.edu
AF: Institute of Geophysics and Planetary Physics, University of California, Los Angeles, Los Angeles, CA 90095-1567 United States
AU: Bale, S D
EM: bale@ssl.berkeley.edu
AF: Space Sciences Laboratory, University of California Berkeley , 7 Gauss Way Centennial Drive at Grizzly Peak Boulevard , Berkeley, CA 94720-7450 United States AB: We have studied the structure and properties of the Moon's wake by means of a two dimensional (global) hybrid simulation (particle ions, fluid electrons). Three different interplanetary magnetic field (IMF) configurations have been examined when the angle between the direction of the solar wind flow and the IMF is 0, 45, and 90 degrees. The Moon acts as a diamagnetic obstacle removing plasma from the solar wind flow. The tail refilling process on the moon's nightside can be described by plasma expansion into a vacuum driven by the thermal motion of particles along the IMF magnetic field lines. We examine properties of the wake-tail formed behind the obstacle embedded in the solar wind flow up to 50 Moon radii using up to 200 million particles in each simulation run with a realistic size for the Moon's body. Results of our study suggest that kinetic processes drive the physical processes in the Moon's wake-tail and their understanding is beyond the ideal MHD description. The orientation of the IMF field influences the structure of the Moon's wake. Counterstreaming plasma in Moon's downstream tail represent an unstable plasma configuration which excites different wave modes whose nature depends on the structure of the tail (i.e. on the orientation of the IMF). We shall provide analysis of these waves for the three cases studied thus far. A comparison of the simulation results with Wind satellite Moon flyby data and Lunar Prospector orbiter data will be carried out wherever possible.
DE: 6250 Moon (1221)
DE: 2159 Plasma waves and turbulence
DE: 2753 Numerical modeling
DE: 2780 Solar wind interactions with unmagnetized bodies
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2004 AGU Fall Meeting