On the types of current patterns of weak geomagnetic disturbances at the polar caps

Abstract

On the basis of geomagnetic data of arctic and antarctic observatories sequences of instant current systems of weak geomagnetic disturbances at the polar caps are constructed for some events. The analysis shows that these disturbances may be represented by the twovortices S q p -system ( DP 2-system type), which is typical in the winter polar cap as well as in the summer one. A close correspondence between variations of the configuration and the intensity of the vortices in both hemispheres is observed at that period. The formation of the electrojets violates this correspondence. The dependence between the disturbance vectors in the evening and the morning sectors of the auroral zone during the periods of DP 2-system existence only and in the presence of the electrojets is examined.