Added value of CMIP6 over CMIP5 models in simulating Indian summer monsoon rainfall

This study assesses the improvements in climate model (CM) simulations for indicative characteristics representing complex dynamics of Indian summer monsoon rainfall for period 1951-2005 in CMIP6 (Coupled Model Intercomparison Project Phase 6). To our knowledge, this is the first preliminary study which compares the performance of models available in CMIP5 and CMIP6 consortium and their multi-model average (MMA). We find a significant improvement in CMIP6 models in capturing the spatiotemporal pattern of monsoon over Indian landmass, especially in the Western Ghats and North-East foothills of Himalayas. We also show that present-day global warming of 0.6 degrees C over Indian landmass is remarkably consistent with the changes in annual maximum 1-day precipitation in MMA of CMIP6, which are in agreement with the observations. Our results suggest that added value in CMIP6 models precipitation simulations is not consistent within CMs used in present study. However, it still provides a precedent to the scientific community in performing future studies on climate change impact assessment.