On a structure of fields and longitudinal currents in Harang discontinuity

Electric fields and currents in the high-latitude ionsphere are cajculated under conditions of a blurred inner boundary of a plasma sheet of arbitrary thickness. The blurred nature of the inner boundary of the plasma sheet results in the twisting of the longitudinal currents system existing at this boundary and that permits to explain the observed distribution of electric fields and longitudinal currents in the Harang discontinuity region. Two tongues streched out eastward and characteristic for the Harang discontinuity region appear in the midnight and midday ionsphere sectors in the picture of plasma convection. In the midnight sector the layer of outflow longitudinal cu rrents represent a continuous region. Inflow currents have a discontinuity near the midnight; before the midnifght they are located more equatoraly than outflow currents, and after the midnight - more polary. In the madday sector the nature of inflow and outflow longitud inflow and outflow longitudinal currents distribution changes in the reverse order