Heating of the solar corona by Alfven waves - self-induced opacity

TL;DR

This paper models how high-frequency Alfven waves create a self-induced opacity at the solar transition region, explaining the heating of the solar corona through a self-consistent MHD approach.

Contribution

It introduces a numerical solution of MHD equations showing how Alfven waves induce a transition layer, advancing understanding of coronal heating mechanisms.

Findings

High-frequency Alfven waves are absorbed at the transition layer.

Low-frequency waves are strongly reflected by the transition layer.

The model predicts a spectral density of Alfven waves in the photosphere.

Abstract

Static distributions of temperature and wind velocity at the transition region are calculated within the framework of magnetohydrodynamics (MHD) of completely ionized hydrogen plasma. The numerical solution of the derived equations gives the width of the transition layer between the chromosphere and the corona as a self-induced opacity of high-frequency Alfven waves (AW). The domain wall is direct consequence of the self-consistent MHD treatment of AW propagation. The low-frequency MHD waves coming from the Sun are strongly reflected by the narrow transition layer, while the high-frequency waves are absorbed - that is why we predict considerable spectral density of the AW in the photosphere. The numerical method allows consideration of incoming AW with arbitrary spectral density. The idea that Alfven waves might heat the solar corona belongs to Alfven, we simply solved the corresponding MHD equations. The comparison of the solution to the experiment is crucial for revealing the heating mechanism.