In this paper, the author present an assessment of the likely climate changes over the Indian subcontinent and the intraseasonal and interannual variability in summer monsoon rainfall as a consequence of increasing greenhouse gas concentrations in the atmosphere as inferred from CSIRO9 climate model simulations. The data obtained from the control and doubled CO2 experiments with the model, each for 24-equilibrium years, are analyzed in this study.
The model demonstrates a reasonable skill in simulating the present-day climate and its interannual variability over the Indian subcontinent. The total seasonal rain ll over India under the influence of southwest monsoon activity as inferred from the control run is in fair agreement with the observed climatology. A rise in area-averaged surface temperature of 2.98° during the monsoon season over India (for land points only) is projected by the model in a doubled C02 atmosphere. Though no significant change in the monsoon onset date is found, an intensification of monsoonal rainfall is simulated by the model in a warmer atmosphere. The seasonal changes in the other hydrological parameters (evaporation and soil moisture) simulated by the model for the doubled C02 atmosphere are also discussed.