2025-04-30 フランス国立科学研究センター（CNRS）
＜関連情報＞
- https://www.cnrs.fr/en/press/twisted-flux-ropes-key-solar-flares-and-atmospheric-heating
- https://iopscience.iop.org/article/10.3847/2041-8213/adb74f
静かな太陽におけるねじれたフラックスロープの偏在性 The Ubiquity of Twisted Flux Ropes in the Quiet Sun
Tahar Amari, Aurélien Canou, Marco Velli, Zoran Mikic, Frederic Alauzet, Eric Buchlin, Jean-François Luciani, Jean-Jacques Aly, and Lucas A. Tarr
The Astrophysical Journal Letters Published: 2025 April 30
DOI:10.3847/2041-8213/adb74f
Abstract
Models and observations have demonstrated that twisted flux ropes (TFRs) play a significant role in the structure and eruptive dynamics of active regions. Their role in the dynamics of the quiet Sun atmosphere has remained elusive, their fundamental relevance emerging mainly from theoretical models showing that they form and erupt as a result of flux cancellation. Here, Hinode high-resolution photospheric vector magnetic field measurements are integrated with advanced environment reconstruction models: TFRs develop on various scales and are associated with the appearance of mesospots. The developing TFRs contain sufficient free magnetic energy to match the requirements of the recently observed “campfires” discovered by Solar Orbiter in the quiet Sun. The free magnetic energy is found to be large enough to trigger eruptions, while the magnetic twist is large enough to trigger confined eruptions, heating the chromosphere. TFRs are also connected to larger-scale magnetic fields such as supergranulation loops, allowing the generation of Alfvén waves at the top of the chromosphere that can propagate along them. High-resolution magnetohydrodynamic simulations, incorporating subsurface dynamo activity at an unprecedented 30 km spatial resolution, confirm that TFRs are ubiquitous products of the permanent small-scale dynamo engine that feeds their formation, destabilization, eruption via flux emergence, submergence, and cancellation of their chromospheric feet, similar to the dynamics driving large-scale eruptive events. Future investigations, especially with the Daniel K. Inouye Solar Telescope and Solar Orbiter, will deepen our understanding of TFRs in the context of atmospheric heating.
