High‐latitude field‐aligned current sources and induced electric fields

Using a simple, planar model of the high‐latitude ionosphere with an enhanced conductivity auroral ring, we compute the electric potential for a pair of field‐aligned current sheets inferred from observations. The relationship of various characteristics of the electric potential pattern to features of the field‐aligned current distribution are elucidated in the context of a generalized field‐aligned current Fourier analysis. On the basis of our analysis and observations to date we conclude that boundary layer dynamo action is the prevalent mechanism in the solar wind/magnetosphere/ionosphere interaction.