Electric fields and currents associated with active aurora

The International Magnetospheric Study (IMS) provided a significant amount of information with respect to the electrodynamics of the auroral ionosphere and near-earth magnetosphere. The present investigation is concerned with the review of a number of studies of which the available data have been used to model the three-dimensional current flow in and near active substorm aurorae. Attention is given to auroral break-up and westward travelling surges, and eastward drifting omega bands. It is found that the omega bands are associated with east-west orientated pairs of up- and downward directed field-aligned currents which drift eastward together with the omega bands with ExB velocity. 27 references