Phase-Mixing and Dissipation of Standing Shear Alfven waves

TL;DR

This paper investigates how standing shear Alfvén waves dissipate through phase mixing in non-uniform plasmas, confirming the exponential damping law's validity for high Lundquist and Reynolds numbers.

Contribution

The study numerically verifies the exponential damping law for standing shear Alfvén waves across a range of high Lundquist and Reynolds numbers, extending previous theoretical results.

Findings

Exponential damping law holds for (R,S) ≥ 10^7.

Dissipation behavior depends on plasma parameters.

Numerical results support theoretical predictions.

Abstract

We study the phase mixing and dissipation of a packet of standing shear Alfv\'en waves localized in a region with non-uniform Alfv\'en background velocity. We investigate the validity of the exponential damping law in time, $\exp(-At^3)$, presented by Heyvaerts & Priest (1983) for different ranges of Lundquist, $S$, and Reynolds, $R$, numbers. Our numerical results shows that it is valid for $(R,S)\geq 10^7$.