The influence of a mini‐magnetopause on the magnetic pileup boundary at Mars

Abstract

3D single fluid non‐ideal MHD simulations are used to predict positions for the bow shock and magnetic pileup boundary (MPB). The positions are in agreement with those calculated from Mars Global Surveyor data. The simulations were run with the strong southern magnetic anomalies facing into the solar wind, and the IMF in either the northward or southward direction. The simulations show that the strong southern magnetic anomalies create a magnetopause‐like structure (i.e., a mini‐magnetopause) in place of an MPB but plasma signatures for both types of boundaries are similar. Distinguishing characteristics include the magnetic field orientation, pressure, and the current. The current regions associated with a mini‐magnetopause are larger in scale and greater in magnitude than those at the MPB. The simulations also show that including non‐ideal MHD physics is important in resolving both the magnetic pileup boundary and the mini‐magnetopause.