Are giant tornadoes the legs of solar prominences?

TL;DR

This study analyzes giant tornadoes on the Sun, revealing their prevalence, rotation, and potential role in prominence eruptions, suggesting they are the legs of solar prominences and may influence solar atmospheric dynamics.

Contribution

It provides the first comprehensive statistical analysis of giant solar tornadoes, linking their properties to prominence eruptions and magnetic field structures.

Findings

201 tornadoes detected in 25 days, averaging 30 at solar maximum

Tornadoes often form groups and are associated with prominence legs

Tornado rotation may twist magnetic structures, leading to eruptions

Abstract

Observations in the 171 AA channel of the Atmospheric Imaging Assembly of the space-borne Solar Dynamics Observatory show tornadoes-like features in the atmosphere of the Sun. These giant tornadoes appear as dark, elongated and apparently rotating structures in front of a brighter background. This phenomenon is thought to be produced by rotating magnetic field structures that extend throughout the atmosphere. We characterize giant tornadoes through a statistical analysis of properties like spatial distribution, lifetimes, and sizes. A total number of 201 giant tornadoes are detected in a period of 25 days, suggesting that on average about 30 events are present across the whole Sun at a time close to solar maximum. Most tornadoes appear in groups and seem to form the legs of prominences, thus serving as plasma sources/sinks. Additional Halpha observations with the Swedish 1-m Solar Telescope imply that giant tornadoes rotate as a structure although clearly exhibiting a thread-like structure. We observe tornado groups that grow prior to the eruption of the connected prominence. The rotation of the tornadoes may progressively twist the magnetic structure of the prominence until it becomes unstable and erupts. Finally, we investigate the potential relation of giant tornadoes to other phenomena, which may also be produced by rotating magnetic field structures. A comparison to cyclones, magnetic tornadoes and spicules implies that such events are more abundant and short-lived the smaller they are. This comparison might help to construct a power law for the effective atmospheric heating contribution as function of spatial scale.