Wave propagation and shock formation in different magnetic structures

TL;DR

This study investigates how wave propagation and shock formation vary across different solar magnetic structures by analyzing spectropolarimetric data, revealing that linear vertical wave propagation dominates energy transfer to the chromosphere.

Contribution

It provides new insights into the dependence of wave propagation characteristics on magnetic flux and confirms linear wave propagation as the main energy transfer mechanism.

Findings

Wave power reaching the chromosphere depends on magnetic structure.

Atmospheric cut-off frequency varies with magnetic features.

Linear vertical wave propagation is the primary energy transfer process.

Abstract

Velocity oscillations "measured" simultaneously at the photosphere and the chromosphere -from time series of spectropolarimetric data in the 10830 A region- of different solar magnetic features allow us to study the properties of wave propagation as a function of the magnetic flux of the structure (i.e. two different-sized sunspots, a tiny pore and a facular region). While photospheric oscillations have similar characteristics everywhere, oscillations measured at chromospheric heights show different amplitudes, frequencies and stages of shock development depending on the observed magnetic feature. The analysis of the power and the phase spectra, together with simple theoretical modeling, lead to a series of results concerning wave propagation within the range of heights of this study. We find that, while the atmospheric cut-off frequency and the propagation properties of the different oscillating modes depend on the magnetic feature, in all the cases the power that reaches the high chromosphere above the atmospheric cut-off comes directly from the photosphere by means of linear vertical wave propagation rather than from non-linear interaction of modes.