{\it f}-mode interactions with thin flux tubes: the scattering matrix

TL;DR

This paper models how surface gravity ({ m f}) modes scatter when interacting with thin magnetic flux tubes in stratified media, revealing dominant scattering into { m f} modes with specific amplitude and phase shifts, and how scattering varies with frequency and magnetic dominance.

Contribution

It provides a detailed calculation of the scattering matrix for { m f} modes interacting with thin flux tubes, improving understanding of wave-magnetic field interactions in stratified media.

Findings

Dominant scattered { m f} mode amplitude is 1.17%.

Scattering into high-order p modes is weak and hard to quantify.

Scattering increases with wave frequency and magnetic dominance.

Abstract

We calculate the scattering effects associated with the interaction of a surface gravity or {\it f} mode with a thin magnetic flux tube embedded in a realistically stratified medium. We find that the dominant scattered wave is an $f$ mode with amplitude and phase of 1.17% and around $49^\circ$ relative to the incident wave, compared to the values of 0.13% and $40^\circ$ estimated from observations. The extent of scattering into high-order acoustic $p$ modes is too weak to be accurately characterized. We recover the result that the degree of scattering is enhanced as (a) the frequency of the incident wave increases and (b) the flux tube becomes magnetically dominated.