Rainfall Pattern inferred from CORDEX-SA Domain Models for Future Warming Scenarios over Northwest Himalayan Region

Abstract

Indian economy is predominantly dependent on cultivation and further India receives more or less 80% of its annual rainfall in the summer monsoon season. Therefore, summer monsoon plays an important role from the economic point of view. Based on the recent study, it is said that the rainfall pattern under the global warming scenarios has undergone changes. The rainfall pattern over the North West Himalayan (NWH) region has become more unpredictable as there is a difference in the amount of rainfall and duration of monsoon; rainfall becomes more intense with shorter duration. The extreme weather condition such as cloud burst, heavy precipitation, flash floods, landslides etc. are happening frequently over that region. It has become very difficult to project rainfall pattern under the different warming scenarios over the mountainous NWH region. However, the rainfall pattern over that region can be projected by utilizing finer resolution Coordinated Regional Climate Downscaling Experiment (CORDEX) models. The present study has been planned to investigate the rainfall pattern from the CORDEX South Asia (CORDEX-SA) domain in a consistent framework for the period 2076 to 2100 under different future warming scenarios compared to the historical period from 1976 to 2000. CORDEX-SA domain simulated fields forced by four well known global models (i.e., MIROC5, MPI-ESM-LR, GFDL-ESM2M and IPSL-CM5A-LR) have been examined in the context of spatio-temporal distribution of rainfall over the NWH region in the rainy season. The downscaled rainfall have been validated against the ground-based IMD gridded rainfall data set. It is inferred from the analysis that models like MIROC5 and MPI-ESM-LR provide the best spatial distribution of downscaled rainfall, although CORDEX domain models are unable to simulate the intensity of rainfall at daily scale compared to IMD data over the NWH region.