Formation and Eruption of an Active Region Sigmoid. II. Magnetohydrodynamic Simulation of a Multistage Eruption

• Published in: The Astrophysical journal 2018-10, Vol.866 (2), p.96
• Main Authors: Jiang, Chaowei, Feng, Xueshang, Hu, Qiang
• Format: Article
• Language: English
• Subjects: Astrophysics; Computational fluid dynamics; Computer simulation; Corona; Coronal magnetic fields; Coronal mass ejection; Eruptions; Evolution; Filaments; Fluid flow; Magnetic field configurations; Magnetic fields; Magnetic flux; Magnetic reconnection; Magnetic structure; Magnetohydrodynamic simulation; magnetohydrodynamics (MHD); methods: numerical; Simulation; Solar activity; Solar activity regions; Solar corona; Solar magnetic field; Space weather; Sun: corona; Sun: coronal mass ejections (CMEs); Sun: flares; Sun: magnetic fields; Topology; Tornadoes; Weather
• ISSN: 0004-637X; 1538-4357
• DOI: 10.3847/1538-4357/aadd08

Solar eruptions, mainly eruptive flares with coronal mass ejections, represent the most powerful drivers of space weather. Due to the low plasma-β nature of the solar corona, solar eruption has its roots in the evolution of the coronal magnetic field. Although various theoretical models of the eruptive magnetic evolution have been proposed, they still oversimplify the realistic process in observation, which shows a much more complex process due to the invisible complex magnetic environment. In this paper, we continue our study of a complex sigmoid eruption in solar active region 11283, which is characterized by a multipolar configuration embedding a null-point topology and a sigmoidal magnetic flux rope. Based on extreme ultraviolet observations, it has been suggested that a three-stage magnetic reconnection scenario might explain the complex flare process. Here we reproduce the complex magnetic evolution during the eruption using a data-constrained high-resolution magnetohydrodynamic (MHD) simulation. The simulation clearly demonstrates three reconnection episodes, which occurred in sequence in different locations in the corona. Through these reconnections, the initial sigmoidal flux rope breaks one of its legs, and quickly gives birth to a new tornado-like magnetic structure that is highly twisted and has multiple connections to the Sun due to the complex magnetic topology. The simulated magnetic field configuration and evolution are found to be consistent with observations of the corona loops, filaments, and flare ribbons. Our study demonstrates that significant insight into a realistic, complex eruption event can be gained by a numerical MHD simulation that is constrained or driven by observed data.