Dislocations in magnetohydrodynamic waves in a stellar atmosphere

TL;DR

This paper investigates wavefront dislocations in magnetohydrodynamic waves within stellar atmospheres, combining theoretical description with observational detection in sunspots to estimate modal contributions.

Contribution

It provides the first observational evidence of wavefront dislocations in MHD waves in sunspots and introduces a method to estimate modal contributions from dislocation charges.

Findings

Dislocations occur in Alfvén and magneto-acoustic waves.

Dislocations are detected in solar chromosphere sunspots.

Modal contributions can be estimated from dislocation charges.

Abstract

We describe the presence of wavefront dislocations in magnetohydrodynamic waves in stratified stellar atmospheres. Scalar dislocations such as edges and vortices can appear in Alfv\'en waves, as well as in general magneto-acoustic waves. We detect those dislocations in observations of magnetohydrodynamic waves in sunspots in the solar chromosphere. Through the measured charge of all the dislocations observed, we can give for the first time estimates of the modal contribution in the waves propagating along magnetic fields in solar sunspots.