Dependence of the Latitude of the Cleft on the Interplanetary Magnetic Field and Substorm Activity.

摘要

The latitudinal motion of the cleft (the polar cusp) associated with the southward interplanetary magnetic field (IMF) and substorm activity is examined. The cleft location is identified on the basis of the location of midday auroras and of electron precipitation (OGO 4 and ISIS 1 satellites). It is found that the IMF and substorm activity control independently the latitude of the cleft and that they can shift the cleft location by 3-4 deg under average conditions. (Author)