Hydrometeorological processes and evaporation from falling rain in Indian sub-continent: Insights from stable isotopes and meteorological parameters

•New Indian Meteoric Water Line which better represents different climatic zones.•Evaporation of rain plays significant role throughout the Indian subcontinent.•Evaporative loss from rain ranges from 4 to 52% in different climatic zones.•Altitude span with high Cloud Liquid Water determines rain isotopic depletion.•Validation by observed rain isotopes proves negative bias in modelled rain isotopes. Rigorous analysis of measured isotopic composition (δ18O and δD) of 556 daily rainwater samples collected at four Indian stations viz., Jammu, Jorhat, Hyderabad and Ahmedabad, is done in conjunction with satellite and model derived meteorological and isotopic parameters to discern prominent hydrometeorological processes and factors in four different climatic zones in the Indian subcontinent. A new Indian Meteoric Water Line (IMWL), better representing the different climatic zones, including the semi-arid western India, has been defined: [δD = (7.6 ± 0.1) δ18O + (8 ± 1); R2 = 0.96; P