気象現象の9年周期について
1963 年 72 巻 3 号 p. 105-109
詳細
1963 年 72 巻 3 号 p. 105-109
Abnormal winter weathers from 1962 to 63 remined us of 9-year periodicity which has been found in the change of winter temperature and snow amount in the northern part of Japan. The reality of 9-year periodidity, however, is not accepted fully by meteorologists owing to the insuffuciency of the statistical significant tests, and the lack of physical explanation on it.
In this paper, the existence of 9-year periodicity has been shown by harmonic analysis with quite small statistical risk in the change of January temperature of Tokyo and number of typhoon hit in a year. The present author suggests that the periodicity may be explained by long periodic change of the tidal force due to the following reasons.
(1) 9-year periodicity is one of main periodicity in the change of tidal force.
(2) Recent statistical investigations prove the existence of semisynodic change of the rainy days in America and Australia.
