Geomagnetic substorm activity associated with magnetic clouds

Abstract

The work to establishment of features generation of magnetic substorms interplanetary magnetic clouds, with participation in this process its sheathes is devoted. Research based on comparison parameter dynamics of magnetic clouds fine structure and clouds sheath with dynamics of auroral AL-index and Dst-index of global geomagnetic activity. Clouds sheath is original source of high-latitude activity and gives start to global magnetic storms. Storm development provided by body magnetic cloud parameters was found. However, separate sheath clouds rarely causes global geomagnetic activity, causing usually weak or moderate geomagnetic storms. The most often source of global disturbances becomes a combination of sheath and body, causing classical strong or multi-step storm.