Interplanetary Shocks in the Magnetosheath: Comparison of Experimental Data With MHD Modeling

A present progress in computer sciences and modeling techniques led to development of variety of MHD models of the solar wind - magnetosphere interaction. The models can reproduce processes on the magnetopause, its reaction to changing upstream conditions and the bow shock is built self-consistently in these models. On the other hand, the models have finite grids that limit a spatial resolution and processes connected with non-Maxwellian distribution cannot be modeled. We investigate in detail a propagation of an interplanetary (IP) shock through the solar wind and magnetosheath using different computational methods and compare the modeling results with a real passage of the IP shock through the magnetosheath. Profiles of the magnetic field and plasma parameters across the shock based on multi-spacecraft observations indicate significant differences between IP shock propagation in the solar wind and magnetosheath. The ramp slopes of the plasma parameters in the magnetosheath are not simultaneous and so sharp as those in the solar wind. Nevertheless, there are overshoots of the proton number density and bulk velocity in the magnetosheath which are not observed in the solar wind. Moreover, all these features are well reproduced by two 3-D MHD models.