Scaling relationships of sub-daily precipitation extremes with temperature for monsoon and non-monsoon months in India

The article reports the research findings of a recent study (Kumar et al., 2022) that analyzed the scaling relationship of sub-daily precipitation extremes with coincident temperature in 14 urban locations across India for both monsoon and non-monsoon seasons considering the pre- and post-1975 global climate shift. The joint probabilistic dependence of sub-daily precipitation extremes on temperature is also examined through bivariate copula. It is noted that the scaling relationships with surface air temperature (SAT) deviate substantially from the Clausius-Clapeyron (CC) scaling rates across different climatic regimes in India. Negative scaling is observed in all the cities during both pre-and post-1975 for monsoon season except Pune (PNQ). For locations Bhopal (BHO), Jaipur (JAI) and Mumbai (BOM), the scaling coefficient decreased in monsoon after 1975. For the non-monsoon season, the scaling coefficient was slightly positive almost everywhere and approximately equal to the CC scaling rate except PNQ, both pre-and post-1975. The non-exceedance probability of extreme rainfall showed stronger dependence on higher temperatures during the monsoon season for BOM and New Delhi (DEL), whereas the opposite was detected in the non-monsoon season pre-1975. Using dew point temperature (DPT) in place of SAT, the precipitation extremes for both Chennai (MAA) and Guwahati (GAU) during pre-1975 and Tiruchirappalli (TRZ) during pre-and post-1975 showed positive scaling with super-CC coefficient values in monsoons.

Reference:

Kumar, S., Chanda, K., & Pasupuleti, S. (2022). Pre-and post-1975 scaling relationships of monsoon and non-monsoon hourly precipitation extremes with coincident temperature across urban India. Journal of Hydrology, 128180.