3D Numerical Simulations of f-Mode Propagation Through Magnetic Flux Tubes

TL;DR

This study uses 3D numerical simulations to analyze how surface gravity waves scatter off magnetic flux tubes of varying sizes, revealing mode dominance depends on tube radius, aiding seismic interpretation of solar magnetic structures.

Contribution

It introduces a simulation approach to understand the seismic signatures of magnetic flux tubes, highlighting mode dependence on tube size, which is a novel insight.

Findings

Kink mode dominates in small flux tubes.

Sausage mode dominates in large flux tubes.

Simulation provides a new tool for seismic analysis of flux tubes.

Abstract

Three-dimensional numerical simulations have been used to study the scattering of a surface-gravity wave packet by vertical magnetic flux tubes, with radii from 200 km to 3 Mm, embedded in stratified polytropic atmosphere. The scattered wave was found to consist primarily of m=0 (axisymmetric) and m=1 modes. It was found that the ratio of the amplitude of these two modes is strongly dependant on the radius of the flux tube: The kink mode is the dominant mode excited in tubes with a small radius while the sausage mode is dominant for large tubes. Simulations of this type provide a simple, efficient and robust way to start understanding the seismic signature of flux tubes, which have recently began to be observed.