Fluid Simulations of Three-Dimensional Reconnection that Capture the Lower-Hybrid Drift Instability

TL;DR

This paper demonstrates that a ten-moment fluid model with a heat flux closure can effectively simulate the lower-hybrid drift instability in 3D magnetic reconnection, capturing key kinetic effects and turbulence dynamics.

Contribution

The study introduces a heat flux closure in a ten-moment fluid model to accurately reproduce the lower-hybrid drift instability in 3D reconnection simulations, bridging kinetic and fluid approaches.

Findings

The fluid model captures key properties of the LHDI.

The saturation level of LHDI leads to strong current sheet kinking.

Initial perturbation magnitude significantly affects turbulence development.

Abstract

Fluid models that approximate kinetic effects have received attention recently in the modelling of large scale plasmas such as planetary magnetospheres. In three-dimensional reconnection, both reconnection itself and current sheet instabilities need to be represented appropriately. We show that a heat flux closure based on pressure gradients enables a ten moment fluid model to capture key properties of the lower-hybrid drift instability (LHDI) within a reconnection simulation. Characteristics of the instability are examined with kinetic and fluid continuum models, and its role in the three-dimensional reconnection simulation is analysed. The saturation level of the electromagnetic LHDI is higher than expected which leads to strong kinking of the current sheet. Therefore, the magnitude of the initial perturbation has significant impact on the resulting turbulence.