Inter-comparison of high-resolution satellite precipitation products over India during the summer monsoon season

Water management and risk hazard analysis demand high-resolution (spatially and temporally) rainfall. The present study evaluates recently developed high-resolution satellite precipitation products such as global precipitation measurement (GPM), Indian National Satellite System (INSAT) multi-spectral rainfall algorithm (IMR), INSAT hydrometer estimation method (HEM), and Tropical Rainfall Measuring Mission (TRMM) for Indian summer monsoon during 2014-2019 against India Meteorological Department (IMD) gridded product. Overall, the GPM is remarkably captured spatial distribution of seasonal mean rainfall over India and monsoon dominated zones (i.e. western ghats, eastern and central India). Most satellite products overestimated the seasonal rainfall except the GPM (6.8 mm day(-1)), closely matched with IMD rainfall (6.5 mm day(-1)). GPM is skillful for different rainfall categories such as light (< 7.5 mm day(-1)), moderate (7.6-64.4 mm day(-1)), and heavy (> 64.5 mm day(-1)) on monthly and seasonal scales over all homogeneous regions. In case of INSAT products, the HEM showed improved results than the IMR for all the rainfall thresholds in all homogeneous regions. Similarly, the evaluation of satellite products for (deficit-year (2015) and normal-year (2016) reveals that GPM is superior to both the INSAT and TRMM rainfall products. The analysis of daily rainfall extremes indicates that GPM rainfall could replicate the same for the lowest, normal and highest rain categories compared with the others. The performance of INSAT rainfall can be improved by merging with rain-gauge data, suitable bias corrections, and providing hydrometeors information.