# High frequency waves in the corona due to null points

## TL;DR

This paper investigates high frequency waves near coronal null points, revealing that slow magneto-acoustic shocks generate secondary shocks at 80 mHz, which could help probe coronal structures.

## Contribution

It provides a detailed analysis of wave generation mechanisms near coronal null points, highlighting the role of shock interactions in producing high frequency waves.

## Key findings

- High frequency waves are generated by shock interactions near null points.
- Secondary shocks produce waves at approximately 80 mHz.
- Wave frequency may be used to probe coronal atmospheric parameters.

## Abstract

This work aims to understand the behavior of non-linear waves in the vicinity of a coronal null point. In previous works we have showed that high frequency waves are generated in such magnetic configuration. This paper studies those waves in detail in order to provide a plausible explanation of their generation. We demonstrate that slow magneto-acoustic shock waves generated in the chromosphere propagate through the null point and produce a train of secondary shocks that escape along the field lines. A particular combination of the shock wave speeds generates waves at a frequency of 80 mHz. We speculate that this frequency may be sensitive to the atmospheric parameters in the corona and therefore can be used to probe the structure of this solar layer.