Electron counts in the neutral sheet and magnetic variations at a geomagnetic longitude associated ground station

From a somewhat speculative explanation, but one largely supported from the literature, of the magnetospheric processes involved in this auroral substorm, a plasma velocity estimate of 0·42 Re/min for the initial phase of the substorm is obtained. These velocities are of the same order as the 0·5 Re/min obtained by Lezniak and Winkler (1970) at 6·6 Re.