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 fo 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.