Interplanetary-magnetosphere coupling during intense geomagnetic storms at solar maximum

Abstract

During the interval of August 16. 1978 - December 28. 1979,90% of the intense geomagnetic storms CDst < -l00nD were preceded by the arrival of interplanetary fast forward shocks at 1AU. as identified with magnetic field and plasma data collected by the ISEE-3 spacecraft. For these events we discuss the interplanetary structures that are associated with the -large-amplitude and long-duration negative Bz fields that are thought to be the main cause of the intense storms. We also present a summary of the interplanetary-magnetosphere coupling functions, based on the magnetopause reconnection process. We end by an overview of the long-term evolution of intense geomagnetic storms such as those associated to the seasonal and solar cycle distributions.