Comparative simulations of Kelvin-Helmholtz induced magnetic reconnection at the Earth's magnetospheric flanks

Abstract

In this work, we investigate the interaction between the solar wind and the Earth’s magnetosphere by conducting 3D Hall-MHD simulations. Specifically, we focus on the development of the Kelvin-Helmholtz instability (KHI) and its crucial role in driving magnetic reconnection and plasma transport at the magnetopause. The KHI is closely linked to plasma turbulence, as turbulent fluctuations contribute to its growth by facilitating energy transfer and mixing at smaller scales and the KHI itself is a driver for turbulence in plasma dynamics. At Earth's magnetopause, this leads to increased vortex and wave activity and the emergence of secondary KH modes. Our work involves analyzing simulation data and comparing the effects of initial magnetic shear on the development of the KHI. The results show that the presence of magnetic shear significantly influences the latitudinal distribution of vortices and magnetic reconnection events, leading to quantitative differences in the system’s evolution. Despite differences in the global magnetic topology, all simulations exhibit the formation of vortices, secondary KH instabilities, and a turbulent mixing layer during the late nonlinear phase of the instability.