ELECTRODYNAMIC STRUCTURAL FEATURES OF THE AURORAL-ZONE AS DEDUCED USING DATA FROM A MERIDIONAL CHAIN OF IONOSPHERIC AND MAGNETIC STATIONS

This study has used ionospheric and magnetic observational data obtain ed at a meridional chain of stations during the high latitude geophysi cal experiment 'Taimir-82' in the winter of 1982-1983. Mean statistica l latitude-time distributions of the occurrence probability of various types of E(s), their blanketing frequency and of the amplitude of geo magnetic field H-variations have been constructed. Based on these dist ributions and taking the E(s) properties into account, an analysis is made of the mutual correspondence of large-scale structures of the aur oral ionosphere and ionospheric currents. Ionospheric currents flow ma inly in the region of high E-layer ionization. With increasing magneti c activity, the zone of currents and the zone of ionization expand sim ultaneously toward lower latitudes. The evening eastward electrojet an d the morning westward electrojet are localized inside the zone of dif fuse auroral precipitation which is responsible for the formation of E (s) type r. The equatorial part of the midnight westward electrojet is also located in the zone of diffuse precipitation which coincides als o with the region of maximum ionization of the E-layer. The polar part of this electrojet, which extends far into the dusk sector, is locate d in the zone of discrete auroral precipitation (a type E(s)). Whereas there exists in the meridional cross-section quite a definite relatio nship between the Harang discontinuity and ionospheric parameters, suc h a relationship is not manifested in the zonal cross-section of the H arang discontinuity.