Two Energy Release Processes for CMEs: MHD Catastrophe and Magnetic Reconnection

TL;DR

This paper explores two key processes, MHD catastrophe and magnetic reconnection, that explain how magnetic energy is rapidly released in the solar corona to produce CMEs and flares, highlighting their roles and interactions.

Contribution

It introduces a combined framework of MHD catastrophe and magnetic reconnection as mechanisms for energy release in CMEs, with new insights into their interplay and observational implications.

Findings

MHD catastrophe can abruptly release stored magnetic energy in the corona.

Magnetic reconnection occurs at current sheets formed during catastrophe, accelerating CMEs.

Proposes observational strategies with KuaFu satellites to study these processes.

Abstract

It remains an open question how magnetic energy is rapidly released in the solar corona so as to create solar explosions such as solar flares and coronal mass ejections (CMEs). Recent studies have confirmed that a system consisting of a flux rope embedded in a background field exhibits a catastrophic behavior, and the energy threshold at the catastrophic point may exceed the associated open field energy. The accumulated free energy in the corona is abruptly released when the catastrophe takes place, and it probably serves as the main means of energy release for CMEs at least in the initial phase. Such a release proceeds via an ideal MHD process in contrast with nonideal ones such as magnetic reconnection. The catastrophe results in a sudden formation of electric current sheets, which naturally provide proper sites for fast magnetic reconnection. The reconnection may be identified with a solar flare associated with the CME on one hand, and produces a further acceleration of the CME on the other. On this basis, several preliminary suggestions are made for future observational investigations, especially with the proposed KuaFu satellites, on the roles of the MHD catastrophe and magnetic reconnection in the magnetic energy release associated with CMEs and flares.