ダイ7ジ エットウタイ チジキ ブモン ケンキュウ カンソク ホウコク チジキ ミャクドウ カンソク

The observation of geomagnetic micropulsations with period from 300 to 0.5 seconds has been carried out by the JARE wintering party at Syowa Station from April, 1966. Geomagnetic signals are registered on a paper chart and a magnetic tape, using a slow speed tape recorder. In this report, characteristics of the recording system are briefly described and the preliminary results mainly for micropulsations of the pc-1 category, observed in 1966, are presented. Pc-1 pulsations are predominantly observed in the daytime at Syowa Station, and about one half of micropulsations with frequency of 0.2-2 Hz show a recurrent structure in f-t display. It is found that pc-1 pulsations are often associated with sudden commencements of magnetic storms which occur around local noon, and that most of ssc pulsations do not have a recurrent structure, although rising frequency of structural elements is noted in f-t display. Some spectral characteristics of pi and pc-2, 3 are also discussed