Filamentation instability associated with dispersive Alfvén wave and solar coronal heating

Abstract

AbstractThis paper presents the nonlinear dynamics of the dispersive Alfvén wave (DAW) in the low-β plasmas (β≪me/mi; known as inertial Alfvén waves) applicable to solar corona. The pump DAW is perturbed by a low-frequency slow Alfvén wave (SW). When the ponderomotive nonlinearities are incorporated in the DAW and SW dynamics, the model equations of DAW and SW turn out to be the modified Zakharov system of equations (MZSE) Growth rate and threshold field for modulational (filamentation) instability have been calculated. The dependence of the growth rate on the perturbation wave number and the pump wave parameters such as k0xλe (inertial) has also been presented. It is obvious from this investigation that DAW can become unstable when it nonlinearly interacts with the SW and modulational instabilities can be triggered. The relevance of these investigations for solar corona has been discussed.