Magnetostatic Modeling of the Mixed Plasma Beta Solar Atmosphere Based on Sunrise/IMaX Data
Abstract
Our aim is to model the threedimensional magnetic field structure of the upper solar atmosphere, including regions of nonnegligible plasma beta. We use highresolution photospheric magnetic field measurements from SUNRISE/IMaX as the boundary condition for a magnetostatic magnetic field model. The high resolution of IMaX allows us to resolve the interface region between the photosphere and corona, but modeling this region is challenging for the following reasons. While the coronal magnetic field is thought to be forcefree (the Lorentz force vanishes), this is not the case in the mixed plasma β environment in the photosphere and lower chromosphere. In our model, pressure gradients and gravity forces are selfconsistently taken into account and compensate for the nonvanishing Lorentz force. Above a certain height (about 2 Mm) the nonmagnetic forces become very weak and consequently the magnetic field becomes almost forcefree. Here, we apply a linear approach where the electric current density consists of a superposition of a fieldline parallel current and a current perpendicular to the Sun's gravity field. We illustrate the prospects and limitations of this approach and give an outlook for an extension toward a nonlinear model.
 Publication:

The Astrophysical Journal
 Pub Date:
 December 2015
 DOI:
 10.1088/0004637X/815/1/10
 arXiv:
 arXiv:1511.05568
 Bibcode:
 2015ApJ...815...10W
 Keywords:

 methods: numerical;
 Sun: chromosphere;
 Sun: corona;
 Sun: magnetic fields;
 Sun: photosphere;
 Astrophysics  Solar and Stellar Astrophysics
 EPrint:
 ApJ, accepted, 6 Pages, 4 Figures