Drift of auroral absorption observed in February 1986 with the scanning beam riometer at Syowa Station

• Main Authors: Kikuchi, Takashi, Yamagishi, Hisao
• Language: English
• Published: National Institute of Polar Research 1990
• Subjects: Syowa Station; Antarc*; Antarctica
• Online Access: https://nipr.repo.nii.ac.jp/record/4081/files/KJ00000036012.pdf; https://doi.org/10.15094/00004081; https://nipr.repo.nii.ac.jp/records/4081

P(論文) The scanning beam riometer at Syowa Station, Antarctica (66.1°inv. lat.) detected drift of auroral absorptions during a severe geomagnetic storm in February 1986. Eastward drifts predominated in the morning sector (0600-0930 MLT) on February 8,1986,with speeds ranging from 1.0 to 3.8km/s. These drift velocities are considerably greater than those (60-700m/s) obtained under a moderately disturbed condition reported by T. KIKUCHI et al. (Ann. Geophys., 8,431,1990) while the drift direction was the same for both cases. The eastward drift takes place with a decrease in the geomagnetic H-component, with its speed being proportional to the H-component deflection from the quiettime level. It is suggested that both the absorption drift and ionospheric currents are subjected to a common earthward electric field in the magnetosphere. Therefore, the high drift velocity may indicate an intensification of the electric field in the magnetosphere. departmental bulletin paper