Simulations of the 2001 Indian Summer Monsoon Onset with a General Circulation Model

Land-atmosphere interactions, in terms of heat and moisture fluxes, are very important processes in the evolution of the Indian monsoon. A series of sensitivity experiments was conducted with a general circulation model of the atmosphere in order to study the influence of vegetation and soil characteristics on the onset of the Indian summer monsoon. Differences in model results are analysed, both in terms of general circulation features and precipitation distribution. The results confirm that the detailed specification of surface boundary conditions is crucial and lead to great differences in the evolution of the monsoon. Soil and vegetation prescription, however, seems to act in a complex and quite conflicting way and can result dissimilar to observations in specific regions.