Direct observations of different sunspot waves influenced by umbral flashes

TL;DR

This study presents observational evidence that umbral flashes modulate various sunspot waves across different atmospheric layers, including the corona, revealing magnetic coupling in sunspot regions.

Contribution

First observational demonstration that umbral flashes influence and modulate sunspot waves from the chromosphere to the corona.

Findings

Sunspot waves are synchronized with umbral flashes.

Sunspot oscillations influence coronal disturbances.

Wave properties can be used to study magnetic coupling.

Abstract

We report the simultaneous presence of chromospheric umbral flashes and associated umbral waves, and propagating coronal disturbances, in a sunspot and related active region. We have analyzed time-distance maps obtained using the observations from Atmospheric Imaging Assembly (AIA) on-board Solar Dynamics Observatory (SDO). These maps show the simultaneous occurrence of different sunspot oscillation and waves such as umbral flashes, umbral waves, and coronal waves. Analysis of the original light curves, i.e., without implementing any Fourier filtering on them, show that the amplitudes of different sunspot waves observed at different atmospheric layers change in synchronization with the light curves obtained from the umbral flash region, thus demonstrating that these oscillations are modulated by umbral flashes. This study provides the first observational evidence of the influence of sunspot oscillations within the umbra on other sunspot waves extending up to the corona. The properties of these waves and oscillations can be utilized to study the inherent magnetic coupling among different layers of the solar atmosphere above sunspots.