HR: 11:50h
AN: SM52A-08 INVITED    [Abstracts]
TI: 3D Multi-species Global MHD Studies Of The Solar Wind Interaction With Mars And Saturn's Magnetospheric Plasma Flow With Titan
AU: * Ma, Y
EM: yingjuan@igpp.ucla.edu
AF: IGPP, UCLA, 6877 Slichter Hall, Los Angeles, CA 90095,
AB: This dissertation presented numerical simulation results of the interaction of the solar wind/magnetospheric plasma flow with weakly magnetized/unmagnetized solar system bodies (Mars and Titan) using a multi-species global MHD model. Mars and Titan are both considered as being weakly magnetized/non-magnetized bodies with well-extended atmospheres. Therefore, the solar wind/magnetospheric plasma flow interacts with the corresponding ionosphere/atmosphere systems directly. A 2nd-order Godunov-type, finite-volume, upwind method was used to solve the multi-species MHD equations. The study of the solar wind interaction with Mars started with a three-species MHD model with Cartesian coordinate grid system, which considered protons in the solar wind and the two dominant heavy ions ({O}₂⁺ and {O}⁺) in the ionosphere, separately. More extensive studies were carried out by using an updated 4-species MHD model with a spherical coordinate grid system, which gives a very good altitude resolution and a more realistic ionosphere. The model results are consistent with the Viking observations of the ionospheric ion density and the MGS measured bow shock locations. Using this updated model, we also studied the effects of crustal magnetic field, solar radiation, magnetic field orientation, charge exchange and impact ionization. A three-dimensional 7-species MHD model was used to study the interaction of Titan's ionosphere and Saturn's magnetosphere. The spherical grid system was used in the calculations to get a good resolution in the ionospheric region. The simulation results have been compared with past Voyager measurements and observations of the first three flybys (Ta, Tb and T5) of Titan by Cassini, which agree reasonably well with the observations. The major advantages and limitations of the multi- species MHD models were also discussed in detail.
DE: 2459 Planetary ionospheres (5435, 5729, 6026)
DE: 2732 Magnetosphere interactions with satellites and rings
DE: 2780 Solar wind interactions with unmagnetized bodies
DE: 6225 Mars
DE: 6281 Titan
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Fall Meeting