INTENSE MAGNETIC CLOUDS AND THEIR INTERACTIONS WITH AMBIENT SOLAR WIND STREAMS

Structure characteristics of typical intense magnetic clouds are discussed for different conditions of ambient solar wind streams, with emphasis on the dynamic processes that govern the interaction between cloud and ambient stream. It is suggested that large magnetic pressure gradient forces at the expanding cloud boundaries are able to accelerate the stream ahead of cloud and decelerate that behind, building up double saw-tooth speed profiles and driving shocks.