Generation of electric fields in the magnetotail with the conductive ionosphere

The problem of generation of electric-fields and currents in the magnetotail under the effect of solar wind viscous friction against a magnetospheric plasma is considered. The investigation is carried out in the framework of MHD-equations. The purpose of the study is to elucidate the role of polar ionosphere with such mechanism in generation of electric and magnetic fields. It is shown that the ionosphere is responsible for forming the structure of longitudinal currents, affects the electric and magnetic field parameters in the magnetotail. The ionospheric conductivity determines dimensions of returning flow region in a plasma layer. The electric field in the tail is oriented from evening to morning in boundary with solar wind regions and from morning to evening in the central one. The boundary of these region division is controlled as well by ionospheric conductivity. The model of the tail considered corresponds to quiet conditions in the magnetosphere