Articles | Volume 15, issue 12
31 Dec 1997
31 Dec 1997

Afternoon mid-latitude current system and low-latitude geomagnetic field asymmetry during geomagnetic storms

A. Grafe, P. A. Bespalov, V. Y. Trakhtengerts, and A. G. Demekhov

Abstract. For four geomagnetic storms of middle intensity the relationship between the low-latitude magnetic field asymmetry using ASY indices and the intensity of the auroral eastward and westward electrojet was considered. It was asked whether there exists a connection between ASY and the eastward electrojet. To answer this question equivalent current systems were estimated in mid-latitudes. It was found that the observations obviously show no correlative relationship between the low-latitude magnetic-field asymmetry and the eastward electrojet, whereas one exists between ASY and the westward electrojet. To explain the generally accepted common three-dimensional current system between the partial ring current and the eastward electrojet, a condensor model of the three-dimensional current system was developed. It could be shown that the short periodic variations of the partial ring current are shielded by the condensor and cannot influence the eastward-electrojet current.