Data-driven Simulations of Magnetic Field Evolution in Active Region 11429: Magneto-frictional Method Using PENCIL CODE

Abstract

Coronal magnetic fields evolve quasi-statically over long timescales and dynamically over short timescales. As of now there exist no regular measurements of coronal magnetic fields, and therefore generating the coronal magnetic field evolution using observations of the magnetic field at the photosphere is a fundamental requirement to understanding the origin of transient phenomena from solar active regions (ARs). Using the magneto-friction (MF) approach, we aim to simulate the coronal field evolution in the solar AR 11429. The MF method is implemented in the open source Pencil Code along with a driver module to drive the initial field with different boundary conditions prescribed from observed vector magnetic fields at the photosphere. In order to work with vector potential and the observations, we prescribe three types of bottom boundary drivers with varying free-magnetic energy. The MF simulation reproduces the magnetic structure, which better matches the sigmoidal morphology exhibited by Atmospheric Imaging Assembly (AIA) images at the pre-eruptive time. We found that the already sheared field further driven by the sheared magnetic field will maintain and further build the highly sheared coronal magnetic configuration, as seen in AR 11429. Data-driven MF simulation is a viable tool to generate the coronal magnetic field evolution, capturing the formation of the twisted flux rope and its eruption.