Two-Dimensional Hybrid Simulations of a Magnetosheath Filament Interaction with the Magnetopause

Abstract
Two-dimensional hybrid simulations are used to investigate the impulsive penetration process when a magnetosheath plasma irregularity interacts with the magnetopause. The irregularity is modeled as a field-aligned filament with an excess density impinging on the magnetopause. Different configurations are used defined by a parallel or anti-parallel magnetic field in both regions (magnetosheath and magnetosphere) and also in the case of sheared magnetic fields. The results show that a MHD approach is not totally usefull and emphasize the kinetic effects of the ions on the propagation of the plasma irregularities and their consequences on the energy balance between the two regions. Moreover, sheared magnetic field configurations allow inferences about the actual solar wind - magnetosphere interaction and show that the threshold conditions for penetration are much more restrictive than MHD results. This study strongly harms the impulsive penetration mechanism to explain the transfer of mass and energy from the magnetosheath to the magnetopshere.