Modulation of Dry and Wet Period Temperatures in India

Temperature-based events such as heatwaves and compound dry hot extremes impact the socio-economic sectors of a nation. In this study, the differential rates of temperature intensification across different seasons and regions in India coupled with dry/ wet climatologies are studied. The analysis is done for both historical observations and future CMIP6 simulations. Further, the temperature intensification rates were linked to established atmospheric feedback mechanisms. Results show that observed temperature intensification rates are positive/negative during dry/wet climatology relative to average climatology. Analysis of feedback mechanisms showed that cooling temperature trends are associated with a decrease in atmospheric aridity (vapor pressure deficit) and an increase in relative humidity. While in southern India, temperature trends are similar for all three climatologies (average, dry, and wet), albeit with different rates of intensification, in northern India, the temperature intensification shows notable contrasting trends during dry and wet climatologies. The highly irrigated Indo-Gangetic Plain region in northern India is found to experience significant cooling temperature trends during dry climatology and these trends are much more prominent during the agricultural Rabi season. Climate change analysis using CMIP6 simulations indicates further exacerbation of temperatures across all regions in the Indian subcontinent and foresees an increased probability of compound extremes in the future.