Numerical simulations of the initiation and the IP evolution of coronal mass ejections.

We present recent results from numerical simulations of the initiation and interplanetary (IP) evolution of Coronal Mass Ejections (CMEs) in the framework of ideal magnetohydrodynamics (MHD). As a first step, the magnetic field in the lower corona and the background solar wind are reconstructed. Both simple, axisymmetric (2.5D) solar wind models for the quiet sun as more complicated 3D solar wind models taking into account the actual coronal field through magnetogram data are reconstructed. In a second step, fast CME events are mimicked by superposing high-density plasma blobs on the background wind and launching them in a given direction at a certain speed. In this way, the evolution of the CME can be modeled and its effects on the coronal field and background solar wind studied. In addition, more realistic CME onset models have been developed to investigate the possible role of magnetic foot point shearing and magnetic flux emergence/disappearence as triggering mechanisms of the instability. Parameter studies of such onset models reveal the importance of the background wind model that is used and of the initiation parameters, such as the amount and the rate of the magnetic flux emergence or the region and the amount of foot point shearing. [ABSTRACT FROM AUTHOR]