The Buildup of the Magnetic Free Energy that Powers Solar Eruptions

Coronal mass ejections (CME)/eruptive flares are the primary drivers of the most destructive space weather ranging from intense solar energetic particle bursts to electric power disruptions. The fundamental origin of these events is the buildup of free energy in the form of the highly nonpotential magnetic field of filaments/prominences in the Sun’s corona. Long-range prediction of CMEs/flares, therefore, requires understanding and modeling the formation of this magnetic field, the so-called filament channel. The formation of filament channels, however, has long been one of the outstanding problems in Heliophysics. We describe a new theory that we have recently developed, helicity condensation, that can explain all the major observed features of filament channels. We present numerical simulations that demonstrate how helicity condensation operates in the case of a coronal active region field and derive time scales for the free energy buildup. We discuss the implications of our results for the space weather modeling of solar eruptive events.  

This work was supported in part by the NASA Living With A Star Program.