Phase mixing of standing Alfven waves with shear flows in solar spicules

TL;DR

This study examines how shear flows and magnetic fields influence the rapid damping of standing Alfven waves in solar spicules, highlighting their role in energy dissipation relevant to coronal heating.

Contribution

It introduces a model considering shear flow and magnetic field effects on Alfven wave dissipation in stratified solar spicules, emphasizing their impact on wave damping rates.

Findings

Shear flow and magnetic field accelerate wave damping.

Standing Alfven waves dissipate within a few periods.

Velocity amplitude increases with height, magnetic perturbation decreases.

Abstract

Alfvenic waves are thought to play an important role in coronal heating and solar wind acceleration. Here we investigate the dissipation of such waves due to phase mixing at the presence of shear flow and field in the stratified atmosphere of solar spicules. The initial flow is assumed to be directed along spicule axis and to vary linearly in the x direction and the equilibrium magnetic field is taken 2-dimensional and divergence-free. It is determined that the shear flow and field can fasten the damping of standing Alfven waves. In spite of propagating Alfven waves, standing Alfven waves in Solar spicules dissipate in a few periods. As height increases, the perturbed velocity amplitude does increase in contrast to the behavior of perturbed magnetic field. Moreover, it should be emphasized that the stratification due to gravity, shear flow and field are the facts that should be considered in MHD models in spicules.