The Monsoon over the Indian Ocean during Summer 1975. Part I: Mean Fields

Abstract

An assimillaiion of surface data collected from ship reports, land and islands stations during summer 1975 is presented. The domain of this study is the summer MONEX area (35?100°E, 25°N-25°S) and the period covers May, June, July, August and September 1975. Objective analysis of the data for 304 individual half-days (an analysis every 12 h) was carried out over the domain for the wind, pressure, air temperature, sea surface temperature and water vapor mixing ratio fields. In this first part, the mean monthly fields are presented and climatological features are discussed. Charts of latent heat transfer are presented. The water vapor cross-equatorial flux (40?100°E) for the complete monsoon season (May-September) is 4.7=1010 tons day?1. It is shown that maximum input takes place in the Arabian Sea (75% of the total flux), especially between 45 and 60°E (more than 50% of the total flux). The cross-equatorial flux into the Bay of Bengal is not negligible, being about ? of that over the western Indian Ocean (25% of the total flux).