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

• Published in: Annales geophysicae (1988) Vol. 15; no. 12; pp. 1537 - 1547
• Main Authors: Grafe, A., Bespalov, P. A., Trakhtengerts, V. Y., Demekhov, A. G.
• Format: Journal Article
• Language: English
• Published: European Geosciences Union 01.12.1997; Copernicus Publications
• Subjects: Earth Sciences; Ocean, Atmosphere; Sciences of the Universe
• ISSN: 1432-0576; 0992-7689; 1432-0576
• DOI: 10.1007/s00585-997-1537-5

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.