Whistler precursor and intrinsic variability of quasi-perpendicular shocks

TL;DR

This paper investigates the structure and variability of whistler precursors in quasi-perpendicular shocks using a two-fluid model, revealing how dissipation influences shock dynamics and wave generation.

Contribution

It introduces a reduced KdV and KdV-Burgers framework to describe whistler precursors and their intrinsic time-dependent behavior in quasi-perpendicular shocks.

Findings

Strong dissipation leads to stationary whistler waves ahead of shocks.

Reduced models capture shock reformation and wave detachment phenomena.

Shock profiles exhibit intrinsic time dependence and reformation cycles.

Abstract

The structure of whistler precursor in a quasi-perpendicular shock is studied within two-fluid approach in one-dimensional case. The complete set of equations is reduced to the KdV equation, if no dissipation is included. With a phenomenological resistive dissipation the structure is described with the KdV-Burgers equation. The shock profile is intrinsically time dependent. For sufficiently strong dissipation, temporal evolution of a steepening profile results in generation of a stationary decaying whistler ahead of the shock front. With the decrease of the dissipation parameter whistler wavetrains begin to detach and propagate toward upstream and the ramp is weakly time dependent. In the weakly dissipative regime the shock front experiences reformation.