Boundary Condition for a Nonstationary Horizontal Ionospheric Current at the Terminator with Allowance for Flowing of a Part of the Current into the Upper Ionosphere and Magnetosphere

Abstract

We consider the boundary condition for horizontal ionospheric currents at the terminator with allowance for the possibility of flowing of a part of the current into the upper ionosphere and magnetosphere. Theoretical models of extremely low frequency field propagation presented in the literature assume that the horizontal ionospheric current component orthogonal to the terminator is continuous at the terminator. A well-known boundary condition for Alfvén waves in a horizontally inhomogeneous ionosphere is used as the basis for theoretical constructs.