Simulations of Filament Channel Formation in a Coronal Magnetic Field
Abstract
A major unanswered problem in solar physics has been explaining the presence of sheared filament channels above photospheric polarity inversion lines (PILs) and the simultaneous lack of structure in the ‘loop’ portion of the coronal magnetic field. The shear inherent in filament channels represents not only a form of magnetic energy, but also magnetic helicity. As a result, models of filament channel formation need to explain not only why helicity is observed above PILs, but also why it is apparently not observed anywhere else in the corona. Previous results (Knizhnik, Antiochos & DeVore, 2015) have suggested that any helicity injected into the coronal field inverse-cascades in scale, a process known as magnetic helicity condensation (Antiochos, 2013). In this work, we present high resolution numerical simulations of photospheric helicity injection into a coronal magnetic field that contains both a PIL and a coronal hole (CH). We show conclusively that the inverse cascade of magnetic helicity terminates at the PIL, resulting in the formation of highly sheared filament channels and a smooth, untwisted corona. We demonstrate that even though magnetic helicity is injected throughout the flux system, it accumulates only at the PIL, where it manifests itself in the form of highly sheared filament channels, while any helicity obtained by the CH is ejected out of the system. We show that the formation of filament channels is both qualitatively and quantitatively in agreement with observations and discuss the implications of our simulations for observations.This work was supported by the NASA Earth and Space Science Fellowship, LWS TR&T and H-SR Programs.
- Publication:
-
AAS/Solar Physics Division Abstracts #47
- Pub Date:
- May 2016
- Bibcode:
- 2016SPD....4710301K