Magnetic tornadoes and chromospheric swirls -- Definition and classification

TL;DR

This paper defines and classifies chromospheric swirls, which are signatures of rotating magnetic structures in the solar atmosphere, and discusses their magnetic nature and observational challenges.

Contribution

It provides a precise definition and introduces a morphological classification of chromospheric swirls into three types, enhancing understanding and detection methods.

Findings

Identified three morphological types of chromospheric swirls: Ring, Split, Spiral

Discussed the magnetic field structures associated with tornadoes

Analyzed the impact of spatial resolution on swirl detection

Abstract

Chromospheric swirls are the observational signatures of rotating magnetic field structures in the solar atmosphere, also known as magnetic tornadoes. Swirls appear as dark rotating features in the core of the spectral line of singly ionized calcium at a wavelength of 854.2 nm. This signature can be very subtle and difficult to detect given the dynamic changes in the solar chromosphere. Important steps towards a systematic and objective detection method are the compilation and characterization of a statistically significant sample of observed and simulated chromospheric swirls. Here, we provide a more exact definition of the chromospheric swirl phenomenon and also present a first morphological classification of swirls with three types: (I) Ring, (II) Split, (III) Spiral. We also discuss the nature of the magnetic field structures connected to tornadoes and the influence of limited spatial resolution on the appearance of their photospheric footpoints.