Morphology of the ionospheric convection pattern during time-dependent solar wind and magnetospheric driving

We use an 18 year database of Super Dual Auroral Radar Network (SuperDARN) data to investigate the morphology of the large-scale ionospheric convection pattern. In particular, we look statistically at the location of the foci of the dawn and dusk convection cells which, according to the theoretical picture of Cowley and Lockwood (1992), are expected to move towards the dayside (nightside) when the Dungey cycle is dominated by magnetopause (magnetotail) reconnection. We use concurrent observations of the solar wind and interplanetary magnetic field to provide a proxy for the level of magnetopause reconnection and ground magnetic indices such as AL to provide an indication of the expected level of magnetotail reconnection. We find that, on average, the cell foci do move as predicted by the theory, but the presence of significant variability is consistent with additional factors being involved in governing the convection morphology at any given instant.

Cowley, S. W. H., and M. Lockwood (1992), Excitation and decay of solar wind-driven flows in the magnetosphere-ionosphere system, Ann. Geophysicae, 10, 103-115.