Some aspects of break and active monsoon over southern Asia during summer

North of 10°N, at least three synoptic phases of the summer monsoon can be identified. Two of these phases—the break and active monsoon—are extremes. Patterns of cloudiness and rainfall for these two phases differ substantially. These indicate differences in the geographic location and intensity of tropospheric energy sources.

Tropospheric circulations over the equatorial Indian Ocean during break and active monsoon also differ. A break is often accompanied by the development of a trough in the lower troposphere northeast of Gan; this appears to enhance rainfall over southeast India. Although cause and effect are difficult to separate using scanty aerological data, synoptic variation over the equatorial Indian Ocean east of 60°–65° E may influence rainfall over western and southern India.