Buildup of Magnetic Shear and Free Energy During Flux Emergence and Cancellation

Abstract

We examine a simulation of flux emergence and cancellation, which shows a complex sequence of processes that accumulate free magnetic energy in the solar corona essential for the eruptive events such as coronal mass ejections (CMEs), filament eruptions and flares. The flow velocity at the surface and in the corona shows a consistent shearing pattern along the polarity inversion line (PIL), which together with the rotation of the magnetic polarities, builds up the magnetic shear. Tether-cutting reconnection above the PIL then produces longer sheared magnetic field lines that extend higher into the corona, where a sigmoidal structure forms. Most significantly, reconnection and upward energy-flux transfer are found to occur even as magnetic flux is submerging and appears to cancel at the photosphere. A comparison of the simulated coronal field with the corresponding coronal potential field graphically shows the development of nonpotential fields during the emergence of the magnetic flux and formation of sunspots.

References in corpus (6)

• Non-linear force-free field modeling of a solar active region around the time of a major flare and coronal mass ejection
• Driving major solar flares and eruptions: a review
• Photospheric flux cancellation and associated flux rope formation and eruption
• Eruption of magnetic flux ropes during flux emergence
• The effect of the relative orientation between the coronal field and new emerging flux: I Global Properties
• On the emergence of toroidal flux tubes: general dynamics and comparisons with the cylinder model

Cited by in corpus (25)

• The Helioseismic and Magnetic Imager (HMI) Vector Magnetic Field Pipeline: SHARPs -- Space-weather HMI Active Region Patches
• Flare-productive active regions
• The origin, early evolution and predictability of solar eruptions
• Forecasting Solar Flares Using Magnetogram-based Predictors and Machine Learning
• Sun-to-Earth MHD Simulation of the 14 July 2000 "Bastille Day" Eruption
• Decoding the Pre-Eruptive Magnetic Field Configurations of Coronal Mass Ejections
• What Sustained Multi-Disciplinary Research Can Achieve: The Space Weather Modeling Framework
• Sympathetic Magnetic Breakout Coronal Mass Ejections from Pseudostreamers
• Numerical Simulations of Flare-productive Active Regions: delta-sunspots, Sheared Polarity Inversion Lines, Energy Storage, and Predictions
• Structure and Evolution of Magnetic Fields Associated with Solar Eruptions (Invited Review)
• Numerical Study on Emergence of Kinked Flux Tube for Understanding of Possible Origin of Delta-spot Regions
• $\delta$-Sunspot Formation in Simulation of Active-Region-Scale Flux Emergence
• First use of synoptic vector magnetograms for global nonlinear force free coronal magnetic field models
• The nonpotentiality of coronae of solar active regions, the dynamics of the surface magnetic field, and the potential for large flares
• On magnetic reconnection and flux rope topology in solar flux emergence
• High speed photospheric material flow observed at the polarity inversion line of a delta-type sunspot producing an X5.4 flare on 7 March 2012
• A Nonlinear Force-Free Magnetic Field Approximation Suitable for Fast Forward-Fitting to Coronal Loops. III. The Free Energy
• Photospheric Shear Flows in Solar Active Regions and Their Relation to Flare Occurrence
• Magnetic Gradient: A Natural Driver of Solar Eruptions
• Magnetic Helicity and Free Magnetic Energy as Tools to Probe Eruptions in two Differently Evolving Solar Active Regions
• MHD Equilibria and Triggers for Prominence Eruption
• Untwisting and Disintegration of a Solar Filament Associated with Photospheric Flux Cancellation
• Plasma flows and magnetic field interplay during the formation of a pore
• Non-Neutralized Electric Current of Active Regions Explained as a Projection Effect
• Time path of turbulence and multi-fractality of magnetic field in the evolution of an active region