Water Vapor Transport over the Indian Ocean during the 1979 Summer Monsoon. Part II: Water Vapor Budgets

Abstract

The analysis is based on wind fields from the European Centre for Medium Range Weather Forecasts and humidity fields derived from a 3-layer precipitable water dataset. After the onset of the monsoon the cross-equatorial water vapor flux W of 50 o E does not vary much; it undergoes significant fluctuations E of that longitude. The bulk of water vapor crossing the W coast of India comes from the Southern Hemisphere. The latitude band between 10 o and 20 o S appears as a major source of moisture during the N summer. The major moisture supply for the W coast of Burma and Thailand is advected over the Bay from the Arabian Sea branch of the monsoon. The early retreat of the 1979 monsoon is associated with a decreasing trend in moisture transport over the Arabian Sea. In the Bay of Bengal, the cross-equatorial flux is not affected by the break/active cycle of the monsoon.-from Authors