Magneto-static Modeling of the Mixed Plasma Beta Solar Atmosphere Based on Sunrise/IMaX Data

0455505 - ASÚ 2016 RIV US eng J - Journal Article
Wiegelmann, T. - Neukirch, A.J. - Nickeler, Dieter Horst - Solanki, S.K. - Martinez Pillet, V. - Borrero, J.M.
Magneto-static Modeling of the Mixed Plasma Beta Solar Atmosphere Based on Sunrise/IMaX Data.
Astrophysical Journal. Roč. 815, č. 1 (2015), 10/1-10/6. ISSN 0004-637X. E-ISSN 1538-4357
R&D Projects: GA ČR GA13-24782S
Institutional support: RVO:67985815
Keywords : numerical methods * Sun chromosphere * Sun corona
Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics
Impact factor: 5.909, year: 2015

Our aim is to model the three-dimensional magnetic field structure of the upper solar atmosphere, including regions of non-negligible plasma beta. We use high-resolution photospheric magnetic field measurements from SUNRISE/IMaX as the boundary condition for a magneto-static 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 force-free (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 self-consistently taken into account and compensate for the non-vanishing Lorentz force. Above a certain height (about 2 Mm) the non-magnetic forces become very weak and consequently the magnetic field becomes almost force-free. Here, we apply a linear approach where the electric current density consists of a superposition of a field-line 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.
Permanent Link: http://hdl.handle.net/11104/0256086