Meeting abstract

AGU Fall Meeting, San Francisco, 6-10 December 1998

Abstract:
2.5 dimensional magnetohydrodynamic simulations of the evolution of interplanetary magnetic clouds in a sheared solar wind flow have been carried out. The CME is injected into a wind comprising a high speed region near the poles and a low speed region toward the equator, such as was observed by the Ulysses satellite at solar minimum. Despite the tendency of such a magnetic cloud to be torn apart, the magnetic tension force associated with the cloud field ensures that the parts of the CME in the high and low speed wind remain magnetically connected. However, the magnetic field lines near the center of the cloud do undergo magnetic reconnection, resulting in the creation of secondary flux ropes embedded inside the cloud. However, in the absence of strong plasma flows into the reconnection site, the reconnection rate is quite slow. CMEs with straight field lines show no such coherence and break into two parts, similar to the case with no magnetic field as presented by Gosling and Riley.