Simulation of Shock Waves in the Interplanetary Medium

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 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 complex IP events involving two CME shocks colliding to each other, as often observed. 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.