Diagnostic modeling of the Indian monsoon onset. Part II: budget and sensitivity studies

Abstract

A one-dimensional diagnostic coupled air-sea model is applied to the analysis of the heat and moisture budgets over the Arabian Sea during the 1979 monsoon onset period. Model results show that the moistening due to horizontal advection tends to alter the radiative fluxes so as to hinder the formation and maintenance of the inversion that characterizes preonset conditions, thus favoring the formation of deep convection. The decrease in ocean mixed-layer temperature, which follows the monsoon onset, acts to reduce the latent heat flux significantly. This effect may influence the duration and intensity of the monsoon, as well as the total precipitation. -from Authors