Anthropogenic warming and intraseasonal summer monsoon variability amplify the risk of future flash droughts in India

Flash droughts, characterized by rapid root-zone soil moisture depletion, pose significant threats to agriculture in India. This study utilizes observational data and simulations from the Community Earth System Model (CESM-LENS) to assess flash drought risks in India. Results indicate that flash droughts primarily occur during the summer monsoon season (June-September), driven by intraseasonal monsoon variability. Positive temperature anomalies during monsoon breaks exacerbate soil moisture depletion, amplified by land-atmospheric feedback. The 1979 flash drought stands out as the worst event, affecting over 40% of the country. Projections suggest a five-fold increase in concurrent hot and dry extremes and a seven-fold increase in 1979-like flash droughts by the end of the 21st century, primarily attributed to anthropogenic warming and intraseasonal monsoon variability.

Vimal Mishra, Saran Aadhar, Shanti Shwarup Mahto