2017/10/24 by Shin Toriumi, Shinsuke Takasao · 68 citations
Physics and Astronomy · #Convection #Convection zone #Coronal mass ejection #Current sheet #Ionosphere and magnetosphere dynamics #Magnetic energy #Magnetic field #Magnetic flux #Magnetic reconnection #Magnetohydrodynamics #Solar and Space Plasma Dynamics #Solar flare #Stellar, planetary, and galactic studies #astro-ph.SR
paper · pdf · doi:10.3847/1538-4357/aa95c2
published in The Astrophysical Journal 850(1), 39 (IOP Publishing) · Accepted for publication in ApJ. Movies for Figures 3, 4, 5, 6, and 7 will be available in the published version
arxiv created 2017/10/24 · openalex created_date 2017/11/10 · openalex publication_date 2017/11/15 · arxiv updated 2017/11/29 · openalex updated_date 2026/08/05
Abstract Solar active regions (ARs) that produce strong flares and coronal mass ejections (CMEs) are known to have a relatively high non-potentiality and are characterized by δ -sunspots and sheared magnetic structures. In this study, we conduct a series of flux emergence simulations from the convection zone to the corona and model four types of active regions that have been observationally suggested to cause strong flares, namely the spot–spot, spot–satellite, quadrupole, and inter-AR cases. As a result, we confirm that δ -spot formation is due to the complex geometry and interaction of emerging magnetic fields, and we find that the strong-field, high-gradient, highly sheared polarity inversion line (PIL) is created by the combined effect of the advection, stretching, and compression of magnetic fields. We show that free magnetic energy builds up in the form of a current sheet above the PIL. It is also revealed that photospheric magnetic parameters that predict flare eruptions reflect the stored free energy with high accuracy, while CME-predicting parameters indicate the magnetic relationship between flaring zones and entire ARs.