Global MHD Simulations of Jupiter's Magnetosphere and Ionosphere for Cassini-Galileo Conditions

The magnetosphere of Jupiter during the time period of the Cassini flyby is modeled using a 3D global magnetohydrodynamic (MHD) code. The simulation includes the entire magnetosphere down to 3 R_J and include the following non-MHD physics to better represent the environment: (1) mass loading due to the Io torus, (2) a parameterized super-thermal particle pressure and (3) an ionospheric model as an inner boundary condition. Upstream conditions are set using Cassini data. We examine bow shock and magnetopause crossings by Cassini and Galileo and find that the model correctly predicts measured crossings. We further find that the nearly simultaneous magnetopause crossings for Galileo and Cassini on 10 Jan 2001 could not have resulted from a steady state magnetosphere. We show that the inflated state of the magnetosphere at the time of the Cassini flyby could have results simply from a low solar wind dynamic pressure. In addition, we will show the magnetospheric and ionospheric configuration under different solar wind dynamic pressure and IMF orientation. The ionosphere is found to retain the same general shape, consistent with the persistent auroral oval observed in UV images of Jupiter's aurora. However, the magnitudes of the field aligned currents and cross polar cap potential do vary and will be presented.