Development of the Total Westward Auroral Electrojet Current Estimates during Intense Substorms

We further develop a simple Strip model of a westward substorm electrojet, based on magnetic field observations along a sparse meridian chain of observing stations. The model has three parameters-the boundaries and the (uniform) electric current density. We illustrate it's performance on CARISMA substorm examples. Introduction of an additional model parameter, describing a deviation from the rectangular to the bell-shape of the current meridional profile proved to be not very productive. Finally we compare these model estimates of the total electrojet strength with the estimates of substorm current wedge, determined using the mid-latitude stations. Both estimates have similar magnitude and change in concert during development of substorm expansion phase. The differences in magnitude at specific time instants may reach factor of two, but are similar to the differences between competing ionospheric electrojet models. The latter suggests, that the actual geometry of electrojet current and current wedge current may differ substantially from the simplest models.