Statistical Analyses on Various Characteristics of Pi-geomagnetic Pulsations at Memambetsu and Kanoya(I)
Sano, Y. & Kurihara, T.
Abstract
Observational data of pi-pulsations at Memambetsu and Kanoya during two solar cycles from 1958 to 1979 are statistically analyzed. The data used are from the Report of the Geomagnetic and Geoelectric Observations (Rapid variations) published yearly by the Kakioka Magnetic Observatory.
In this paper, secular variations on various characteristics of pi-pulsations such as their occurrence frequency, period, amplitude and so on are mainly analyzed with respect to their solar cycle dependences. It is confirmed from the present study that there is the well-known inverse relation between the occurrence frequency of pi-pulsations and the solar activity. A distinct solar cycle dependence is found in the secular variation of the period. As for the amplitude, such a distinct solar cycle dependence is not seen so clear in the present analysis.
However, the above-mentioned features are considerably different between the two solar cycles. It is not well understood whether or not these differences are essential, because it will be pointed out that a great change of the observational bases at both stations has been taken place since 1974.
