TOTAL OZONE IN THE MOST HUMID MONSOON REGION

Simple analysis of about fifteen years of monthly total ozone data in the light of associated meteorological processes has been carried out in the tropical and subtropical regions of northern hemisphere. A well marked trough in total ozone has been observed in July and August ove r the most humid part of the region, which comes under the influence o f monsoon circulation. It appears that the occurrence of the trough ma y be due to the lifting of air mass by the intense convective activity over areas of the low level convergence, which is fed normally from t he equatorial belt. Also, the possible occurrence of stratospheric fou ntain due to the existence of the coldest air around the tropopause ov er the entire Southeast Asia and adjacent west Pacific ocean, may be p laying some role to produce this feature.