CME Shock Evolution on Different Background Winds

Authors: S. Poedts, B. Van der Holst, C. Jacobs, I. Chattopadhyay, D. Banerjee, D. Shapakidze, E. Chane
Affiliation: Centre for Plasma Astrophysics, K.U.Leuven

The shocks in the solar corona and interplanetary (IP) space caused by fast Coronal Mass Ejections (CMEs) are simulated numerically and their structure and evolution is studied in the framework of magnetohydrodynamics (MHD). Due to the presence of three characteristic velocities and the anisotropy induced by the magnetic field, CME shocks generated in the lower corona can have a complex structure and topology including secondary shock fronts, over-compressive and compound shocks, etc. The evolution of these CME shocks is followed during their propagation through the solar wind and, in particular, though the critical points in the wind.
Particular attention is given to the effect of the background wind. Different, 'frequently used' wind models are reconstructed with the same numerical code and the same resolution. Also different, 'popular' CME models are reconstructed. Then, the different CME models are combined with the different wind models. The results are sometimes surprising.
The CME shocks are important for `space weather' because they can easily be observed in radio wavelengths. This makes it possible to track the position of the CMEs/magnetic clouds and, hence, to follow their propagation through the corona.