Climate change projections for Cuddalore district of Tamil Nadu; India using a regional climate model-PRECIS

摘要

This study presents the regional climate change over Cuddalore district of Tamil Nadu state, India by using PRECIS, a Regional Climate Model (RCM) developed by Hadley Centre-UK Met office. The model is run with 25km x 25km resolution by using lateralboundary conditions from the Global Climate Model (GCM) - HadCM3Q at the emission rate of SRES A1B scenarios. The results are considered from the ensemble member HadCM3Q0 running over a period of 130 years to predict the future climate change. The analyses concentrate on maximum temperature, minimum temperature and rainfall over the region. For Cuddalore district as a whole, the projections of maximum temperature show an increase of 1.2 °C, 1.7 °C and 3.4 °C for the periods 2020s, 2050s and 2080s respectively with respect to baseline period (1970-2000). Similarly, the projections of minimum temperature show an increase of 1.2 °C, 2.3 °C and 3.6 °C respectively. The annual rainfall projections for the three projections indicate a general decreasein rainfall being about 7%, 5% and 2% respectively; however, some exceptions are noticed over coastal areas where there is an increase in rainfall intensities are seen. The trend analyses have been performed using Mann-Kendall trend test at 0.05 significance level for both surface temperatures and rainfall data series and the increasing trends in case of temperatures indicate significant trends.