CLIMATIC RESPONSE OF THE INDIAN SUBCONTINENT TO DOUBLED CO2 CONCENTRATIONS

Results from the United Kingdom Meteorological Office (UKMO) coupled c limate model have been analysed over the Indian subcontinent in order to validate the model's performance and to assess the changes in clima te and its variability in a simulation with a 1 per cent increase per year in CO2 (compound). The model produces a reasonable simulation of present-day climate over the Indian subcontinent. At the time of CO2 d oubling, the model simulates temperature increases of the order of 1 K to 4 K over the Indian subcontinent during winter and monsoon seasons . The model-simulated monsoon circulation shifts by 10 degrees latitud e towards the north and intensifies by approximately 10 per cent in th e warmer atmosphere. The interannual variability of monsoon onset date s and intraseasonal variability of monsoon rainfall are not significan tly different when the CO2 concentration doubles. However, the model s imulates increased interannual variability of the monsoon rainfall and a greater number of heavy rainfall days during the monsoon.