MHD simulation of electric currents in the solar atmosphere caused by photospheric plasma motion

Abstract

Photospheric plasma motion may cause the buildup of electric currents in the solar atmosphere. These electric currents may then dissipate and heat the corona, cause EUV and X-ray Bright Points (BPs) and trigger flares. In this work we use a 'data driven' 3D MHD model to study the generation of electric currents in the solar atmosphere by photospheric plasma motion. The model was applied to photospheric measurements below an observed EUV-BP. The observed photospheric magnetic field and the derived horizontal plasma motion were used as initial and boundary conditions of a simulation. The horizontal motion gave rise to electric currents in the chromosphere, transition region and lower corona. The currents formed in the area where the motion was applied and above the main concentrations of the photospheric magnetic field.