THEMIS observations of unusual bow shock motion attending a transient magnetospheric event

摘要

We present a multipoint case study of solar wind and magnetospheric observations during a transient magnetospheric compression at 23:19 UT on 15 October 2008. We use high time resolution magnetic field and plasma data from the THEMIS and GOES 11/12 spacecraft to show that this transient event corresponded to an abrupt rotation in the IMF orientation, a change in the location of the foreshock, and transient outward bow shock motion. We employ results from a global hybrid code model to reconcile the observations indicating transient inward magnetopause motion with the outward bow shock motion.