On the influence of environmental parameters on mixing and reconnection caused by the Kelvin-Helmholtz instability at the magnetopause

Abstract

The process feeding the development of a large boundary layer at the interface between the solar wind and the magnetosphere during northward interplanetary magnetic field is still not fully understood, though the Kelvin-Helmholtz instability (KHI) being the major actor is in good agreement with the observations so far. In this article, we study the different configurations than can occur in the KHI scenario in a three-dimensional Hall-MHD setting, where the double mid-latitude reconnection (DMLR) process exposed by Faganello et al. [Europhys. Lett. 100, 69001 (2012)] is triggered by the equatorial roll-ups. Their previous work is extended here with, in particular, a larger simulation box and the addition of a density contrast. The influence of various parameters on the growth rate of the KHI and thus the efficiency of the DMLR is assessed. In the scope of assessing the effect of the Hall term on the physical processes, the simulations are also performed in the MHD frame. These different configurations may have discernible signatures that can be identified by spacecraft diagnostics; therefore the data that would be recorded by spacecrafts during such an event are simulated.