Does the IMF High Latitude Convection?

One of the paradigms of present day magnetospheric physics is that the interplanetary magnetic field at the dayside magnetopause controls the shape of the high-latitude convection pattern and the magnitude of the cross polar cap potential. From this viewpoint, IMF-derived statistical models of high-latitude convection can readily be used to carry out studies of plasma transport and evolution in both the ionosphere and magnetosphere. While there appears to be underlying structure to the convection patterns that is well represented by IMF orientation, studies being carried out with the SuperDARN radar network indicate that the IMF magnitude and orientation does not provide a good measure of the instantaneous cross polar cap potential. Rather the cross polar cap potential exhibits sharp transient increases in a manner discussed by Lockwood and Cowley in the early 1990s. The effects are most apparent in the vicinity of the cusp, but can be observed at other local times. Transient latitudianlly-confined regions of strong convection are the most obvious feature of these potential enhancements. In this paper, we present examples of this phenomena as observed with SuperDARN and discuss its implications.