Cloudiness Fluctuations during the Summer Monsoon

Abstract

Based on daily satellite cloudiness data over the tropical belt between 30S and 30N during the northern hemispheric summer from June 1 to September 15 for the eight years 1965 to 1972, cloudiness changes over the monsoon region were found to be positively correlated with those over the Malaysia-Indonesia region, while marked negative correlation was encountered over the African continent, the equatorial Indian Ocean and the western North Pacific. Through computations of time lag correlation, it was found that the zones of either positive or negative correlation propagated northwards through the equatorial Indian Ocean and the Indian subcontinent with an average speed of about 1° latitude per day.