Numerical modeling of coronal magnetic fields
The interplay of plasma flows and the embedded magnetic field is the ultimate driver of the dynamics in the solar atmosphere. The temporal evolution of the large-scale corona can be understood as the transition between equilibrium states, interrupted occasionally by eruptive processes that are driven by resistive instabilities. In order to understand the associated reconfigurations, the knowledge of the involved magnetic field structures and plasma flows is essential. To date, however, no direct measurements of the physical conditions in the solar atmosphere are available on a routine basis and we aim to approximate the associated physical quantities by numerical modeling. This allows us to look at the quasi-static temporal magnetic evolution of coronal volumes above active regions.
The knowledge of the magnetic field configuration in the outer solar atmosphere is crucial for the interpretation of observed features associated to solar eruptions. We compensate the lack of routine measurements of the 3D magnetic field vector by reconstructing the nonlinear force-free field, consistent with vector magnetic field measured in and around of active regions on the solar surface. We study the storage prior to and the release of magnetic energy after solar eruption with the help of nonlinear force-free magnetic field models. In particular, we investigate the relation of observed emission features to particular magnetic field configurations and the places of energy storage and/or release.