Forward Modelling of Standing Kink Modes in Coronal Loops II. Applications

TL;DR

This paper develops forward models of standing kink modes in coronal loops to interpret EUV observations, aiding in plasma diagnostics and understanding coronal heating through simulation and matching of observed oscillations.

Contribution

It introduces a forward modelling approach for coronal loop oscillations, enabling better interpretation of EUV observations and identification of oscillation properties.

Findings

Forward models can identify oscillation overtone and polarization.

Models reproduce amplitude and phase profiles of oscillations.

Predicts harmonic periodicities in emission and loop width.

Abstract

Magnetohydrodynamic waves are believed to play a significant role in coronal heating, and could be used for remote diagnostics of solar plasma. Both the heating and diagnostic applications rely on a correct inversion (or backward modelling) of the observables into the thermal and magnetic structures of the plasma. However, owing to the limited availability of observables, this is an ill-posed issue. Forward Modelling is to establish a plausible mapping of plasma structuring into observables. In this study, we set up forward models of standing kink modes in coronal loops and simulate optically thin emissions in the extreme ultraviolet bandpasses, and then adjust plasma parameters and viewing angles to match three events of transverse loop oscillations observed by the Solar Dynamics Observatory/Atmospheric Imaging Assembly. We demonstrate that forward models could be effectively used to identify the oscillation overtone and polarization, to reproduce the general profile of oscillation amplitude and phase, and to predict multiple harmonic periodicities in the associated emission intensity and loop width variation.