Comprehensive Synthesis of Magnetic Tornado: Co-spatial Incidence of Chromospheric Swirls and EUV Brightening

TL;DR

This study uses radiative MHD simulations to demonstrate that magnetic tornadoes cause observable EUV brightenings in the corona, linking chromospheric swirls to coronal heating phenomena like solar campfires.

Contribution

It provides the first detailed synthesis linking magnetic tornadoes to coronal EUV brightenings, highlighting their role in small-scale solar energetic events.

Findings

Coronal EUV brightening width ~2 Mm observed above chromospheric swirls.

Brightenings are detectable in SDO/AIA 171 A and Solar Orbiter/EUI 174 A channels.

Magnetic tornadoes may explain small-scale EUV brightenings such as solar campfires.

Abstract

Magnetic tornadoes, characterized as impulsive Alfven waves initiated by photospheric vortices in intergranular lanes, are considered efficient energy channels to the corona. Despite their acknowledged importance for solar coronal heating, their observational counterparts from the corona have not been well understood. To address this issue, we use a radiative MHD simulation of a coronal loop with footpoints rooted in the upper convection zone, and synthesize the chromospheric and coronal emissions corresponding to a magnetic tornado. Considering SDO/AIA 171 A and Solar Orbiter/EUI 174 A channels, our synthesis reveals that the coronal response to magnetic tornadoes can be observed as an EUV brightening of which width is ~2 Mm. This brightening is located above the synthesized chromospheric swirl observed in Ca II 8542 A, Ca II K, and Mg II k lines, which can be detected by instruments such as SST/CRISP, GST/FISS, and IRIS. Considering the height correspondence of the synthesized brightening, magnetic tornadoes can be an alternative mechanism for the small-scale EUV brightenings such as the solar "campfires''. Our findings indicate that coordinated observations encompassing the chromosphere to the corona are indispensable for comprehending the origin of coronal EUV brightenings.