Pressure anisotropy generation in a magnetized plasma configuration with a shear flow velocity

TL;DR

This paper investigates how the Kelvin Helmholtz instability in magnetized plasmas with shear flows can generate pressure anisotropy, influencing plasma stability and potentially triggering mirror or firehose instabilities.

Contribution

It demonstrates the nonlinear evolution of KHI in magnetized plasmas with shear flows and explores the resulting pressure anisotropy and its impact on plasma stability.

Findings

Pressure anisotropy is generated inside the shear region.

Anisotropy can trigger mirror or firehose instabilities.

Implications for solar wind and magnetospheric plasma dynamics.

Abstract

The nonlinear evolution of the Kelvin Helmholtz instability in a magnetized plasma with a perpendicular flow close to, or in, the supermagnetosonic regime can produce a significant parallel-to-perpendicular pressure anisotropy. This anisotropy, localized inside the flow shear region, can make the configuration unstable either to the mirror or to the firehose instability and, in general, can affect the development of the KHI. The interface between the solar wind and the Earth's magnetospheric plasma at the magnetospheric equatorial flanks provides a relevant setting for the development of this complex nonlinear dynamics.