A new method to derive “instantaneous” high‐latitude potential distributions from satellite measurements including auroral imager data

Electric field, magnetic field, auroral imager and particle observations obtained on the Viking satellite for one dusk‐dawn crossing through the polar cusp, are used to illustrate a new promising technique to derive “instantaneous” pictures of the high‐latitude electrodynamics. Global electric field distributions are calculated using as input UV‐imager data of the auroral distribution and in situ measurements of the electrodynamical parameters along the Viking orbit, which are combined with measured average distributions of field‐aligned currents (Region 1 and 2) and conductivities representing the diffuse auroral background. The input data (j∥ and ΣP, ΣH) with contributions from both the diffuse auroral background and active regions, and the output data (E) are tested and calibrated to the Viking measurements by point‐by‐point quantitative comparisons along the magnetic footpoint of the satellite. The calculations are done iteratively to refine and improve both the input and the output. The results demonstrate that selfconsistent and realistic solutions of the prevailing “instantaneous” auroral electrodynamics are possible to obtain in this manner.