Future precipitation extremes over India from the CORDEX-South Asia experiments

Abstract

Under a warming climate scenario, precipitation extremes are projected to increase as indicated by both observations and climate model simulations in the previous studies. In this study, we have considered five regional climate simulations under Coordinated Regional Climate Downscaling Experiment-South Asia domain (CORDEX-SA) to study changes in precipitation extremes over India in the near (2020–2049) and far (2070–2099) future under changing climate scenario with respect to different representative concentration pathways (RCPs)—4.5 and 8.5. Extremes in precipitation are studied and described here using a set of climate indices as defined by the joint CCL/CLIVAR/JCOMM Expert Team (ET) on Climate Change Detection and Indices (ETCCDI). The study reveals that CORDEX-SA simulations under scenarios of increasing greenhouse gas concentration indicate a marked increase in the frequency of wet precipitation extremes over central India in both the near and far future (2070–99) as well as a consistent increase throughout the twenty-first century as indicated by trend values. Simultaneously, dry precipitation extremes show a decreasing trend in most of the simulations. However, the distribution of changes varies widely in its magnitude and sign across the Indian region along with a wide intermodel uncertainty. In the far future and under the intensified scenario RCP8.5, the changes seem to be much more pronounced than those in the near future and less intensified scenario RCP4.5.