MHD Waves in the coronal holes

TL;DR

This paper reviews recent high-resolution observations of MHD waves in coronal holes, highlighting their properties, dissipation, and potential role in accelerating the fast solar wind.

Contribution

It provides a comprehensive review of recent advances in understanding MHD waves in coronal holes, including their identification, behavior, and dissipation mechanisms.

Findings

Detection of compressive slow MHD waves in coronal holes

Observation of damping in Alfven waves from spectral line width variation

Possible link between MHD waves and high-speed quasi-periodic upflows

Abstract

Coronal holes are the dark patches in the solar corona associated with relatively cool, less dense plasma and unipolar fields. The fast component of the solar wind emanates from these regions. Several observations reveal the presence of magnetohydrodynamic (MHD) waves in coronal holes which are believed to play a key role in the acceleration of fast solar wind. The recent advent of high-resolution instruments had brought us many new insights on the properties of MHD waves in coronal holes which are reviewed in this article. The advances made in the identification of compressive slow MHD waves in both polar and equatorial coronal holes, their possible connection with the recently discovered high- speed quasi-periodic upflows, their dissipation, and the detection of damping in Alfven waves from the spectral line width variation are discussed in particular.