Ionospheric Signatures of Magnetospheric Boundary Phenomena

Abstract

The coupling of momentum and energy from the solar wind to the ionosphere remains one of the central questions of solar terrestrial physics. Here we review coupling phenomena with particular attention to effects taking place on a time scale of minutes rather than hours. On this time scale, which is comparable to the travel time for transient phenomena like Alfvén waves across the system, the links in the coupling of the system become more evident as lags are detectable. The search for the low altitude counterpart of magnetopause phenomena and transitory reconnection, in particular has led to the discovery of unexpected new effects, vortices, field aligned current systems and disturbances associated with solar wind pressure changes.