A Quasi-Stationary Appearance of 30 to 40 Day Period in the Cloudiness Fluctuations during the Summer Monsoon over India

Abstract

By using the cloudiness data from 1966 to 1972, a quasi-stationary appearance of 30 to 40 day period was confirmed during the summer monsoon season over India, which is recently found in the data for 1973 as a predominant mode of the monsoon fluctuations (Yasunari, 1979). In the same manner as the result of Yasunari (1979), the fluctuation of this mode shows a northward movement over India-Indian Ocean area in each year. This periodicity seems to appear annually except for the severe drought years such as 1972.