Geomagnetic perturbations in the southern polar cap

Abstract

The energy input in the non-diumal auroral ionosphere from the surrounding of the magneto tail neutral sheet enhances the auroral electrojets. whose variations are reflected by the ground level geomagnetic field within the polar caps. The subject of the present study is to determine the significance of auroral zone geomagnetic indices in polar latitudes. For this purpose perturbations of the years 1967. 68 and 69 are analyzed. In contrast with the criteria for defming perturbations in other latitudes, we consider variations in the geomagnetic activity indices AE. AL and AU.