Influence of collisional heating on the current generation in moving mid-latitude sporadic E-layers

Abstract

A theoretical analysis of local heating processes above the borders of night-time midlatitude dense sporadic E-layers moving under the action of strong acoustic impulses in the ambient plasma of lower density at altitudes of 90 km to 130 km is done. It is seen, that a large velocity of motion of the layer generates a strong Hall current in the layer closed by an external circuit. The field-aligned currents of the external circuit can cause remarkable heating of the electron component by collisions with the neutral particles. As a consequence the field-aligned conductivity in the external circuit is considerably reduced and the Hall current in the sporadic layer becomes smaller. But the estimates show, that the Hall current can nevertheless reache values above the threshold of the excitation of Farley-Buneman waves. Besides it can be possible, that the field-aligned currents generate ion-acoustic and drift waves near the borders of the sporadic layers.