Three-dimensional current systems and electric fields during active aurora

Using data from International Magnetospheric Study arrays of ground based instruments, models of three dimensional current flow associated with active auroras were derived. It is found that intensive localized field aligned currents are associated with the major features of active auroras in the whole nightside portion of the auroral oval. The primary auroral particle precipitation leads to ionospheric conductivity gradients and resulting electric polarization fields. Ionospheric polarization fields strongly influence the formation of magnetospheric substorm current systems.