Self-consistent magnetohydrodynamic equilibria for the closure of field-aligned currents in the ionosphere

Results are presented of numerical calculations of self-consistent equilibria based on a simple fluid model for the interaction of plasma and neutral gas in the lower ionosphere (E and F layer). The model focuses on the aspect of the closure of field-aligned (Birkeland) currents which flow into and out of the lower ionosphere. The dependence of the current structure on the parameters of the model and on the boundary conditions is investigated. It is shown that the model is largely consistent with the observed large scale features of the ionospheric current system. (C) 1996 American Institute of Physics.