Simulations of Shock Structures of a Flare/CME Event in the Low Corona

Jens Pomoell1, Rami Vainio1, Silja Pohjolainen2

1Department of Physics, University of Helsinki, Finland
2Department of Physics and Astronomy, University of Turku, Finland

We study the MHD processes related to a flare/CME event in the lower solar corona using numerical simulations. Our initial state is an isothermal gravitationally stratified corona with an embedded flux rope magnetic field structure. The eruption is driven by applying an artificial force to the flux rope, enabling us to study the shock structures created by CMEs with different height-time profiles. The results show that as the flux rope rises, a shock structure is formed, reaching from ahead of the flux rope all the way to the solar surface. Thus, two main shock fronts are created, one front moving away from the Sun and another sweeping the solar surface. The relation to observed wave phenomena on the solar disk, and formation times of the CME-driven shocks are discussed. In addition, we discuss the radio emissions produced by the shocks under different conditions in the ambient corona.