A nonlocal wave-wave interaction among Alfven waves in an intermediate-beta plasma

TL;DR

This paper introduces a nonlocal energy transfer mechanism between large-scale MHD Alfven waves and small-scale kinetic Alfven waves in intermediate-beta plasmas, relevant to solar wind and corona phenomena.

Contribution

It presents a novel nonlocal coupling process enabling direct energy transfer from large to small scales in plasma wave interactions.

Findings

Interaction exists when plasma beta exceeds electron-to-ion mass ratio.

The mechanism explains the presence of electron-scale kinetic Alfven waves.

Potential application to solar wind and corona observations.

Abstract

A nonlocal coupling mechanism to directly transfer the energy from large-scale Magnetohydrodynamic(MHD) Alfven waves to small-scale kinetic Alfven waves is presented. It is shown that the interaction between a MHD Alfven wave and a reversely propagating kinetic Alfven wave can generate another kinetic Alfven wave, and this interaction exists in the plasmas where the thermal to magnetic pressure ratio is larger than the electron to ion mass ratio. The proposed nonlocal interaction may have a potential application to account for the observed electron scale kinetic Alfven waves in the solar wind and solar corona plasmas.