A model for the electric fields and currents during a strong Ps 6 pulsation event

On April 21, 1985, an intense Ps 6 pulsation event was observed with the EISCAT radar and the EISCAT magnetometer cross. These measurements serve as a reference for a new electrostatic model for the ionospheric conductances, electric fields, and currents of the auroral structures associated with the pulsations, whose auroral signatures are the Ω bands. All parameters are essentially derived from the input field‐aligned current distribution. By varying this distribution and a few free parameters in the relation between the conductances and the upward current, the model is adjusted to the data. We find that by a rearrangement of the upward current from a one‐dimensional sheet configuration to tonguelike poleward extensions the observed event is reproduced in a satisfactory way. Compared to previous works, the Hall current is modulated in a different, less symmetric way, and considerably lower field‐aligned current densities are required.