Mode transformation and frequency change with height in 3D numerical simulations of magneto-acoustic wave propagation in sunspots

TL;DR

This study uses 3D numerical simulations to analyze how magnetoacoustic waves transform and change frequency with height in sunspots, comparing results with theory and observations to understand wave behavior and energy flux in the solar atmosphere.

Contribution

It provides new insights into mode transformation and frequency variation of magnetoacoustic waves in sunspots through detailed 3D simulations and comparison with observational data.

Findings

Chromospheric oscillation frequency decreases with distance from sunspot axis.

Energy flux of wave modes, including Alfvén mode, is quantified.

Simulation results align with theoretical predictions and observations.

Abstract

Three-dimensional numerical simulations of magnetoacoustic wave propagation are performed in a sunspot atmosphere with a computational domain covering from the photosphere to the chromosphere. The wave source, with properties resembling the solar spectrum, is located at different distances from the axis of the sunspot for each simulation. These results are compared with the theory of mode transformation and also with observational features. Simulations show that the dominant oscillation frequency in the chromosphere decreases with the radial distance from the sunspot axis. The energy flux of the different wave modes involved, including de Alfv\'en mode, is evaluated and discussed.