Possible future rainfall over Gangetic Plains (GP), India, in multi-model simulations of CMIP3 and CMIP5

Abstract

The Gangetic Plain (GP) of India is much sensitive to rainfall due to its large spatial and temporal variability, and therefore, Coupled Model Intercomparison Project phases 3 and 5 (CMIP3 and CMIP5)-simulated rainfall is analysed over the GP. Model evaluation is carried out with observed rainfall of India Meteorological Department (IMD) and Global Precipitation and Climatology Project (GPCP). Community Climate System Model version 3 (CCSM3), Hadley Centre Global Environment Model (HadGEM) and Model for Interdisciplinary Research on Climate (MIROC) (Hires) of CMIP3 and CCSM4, CESM1 (WACCM) and CESM1 (CAM5) of CMIP5 sound well with observations. In CMIP3, projected future changes in June-July-August-September (JJAS) rainfall show either 5–15 % excess or 5 % deficit in CCSM3 (A2 scenario) and 10 % deficit in HadGEM1. In B1, MIROC (Hires) shows 5–10 % deficit. Under A1B scenario, deficit is possible in MIROC (Hires) and HadGEM1. In CMIP5, CESM1 (CAM5) shows 5–15 % deficit in Representative Concentration Pathway (RCP) 4.5. CCSM4 and CESM1 (WACCM) show 10–20 % excess while 5–15 % deficit is possible in CESM1 (CAM5) in RCP 8.5.