During the 2022 Asian summer monsoon, southwestern Pakistan, which usually stays relatively dry, saw unprecedented rainfall. Between 300 and 1,200 percent of the expected precipitation fell across the region, flooding one-third of the country, affecting 30 million people, and resulting in significant loss of life. A new study published in the Quarterly Journal of the Royal Meteorological Society connected the extreme event to warm sea-surface temperatures in the tropical Indian and Pacific Oceans. This finding advances efforts to predict extreme weather and enhance disaster preparedness.
Through this research, H. Annamalai of the University of Hawaiʻi at Mānoa works toward the objectives of multiple awards from the Climate Program Office. The Modeling, Analysis, Predictions, and Projections (MAPP) program supported Annamalai through grants to develop process-oriented diagnostics, which assess and improve how climate processes are represented in models. MAPP and the National Integrated Drought Information System (NIDIS) supported this work through another grant to understand precipitation and drought patterns by analyzing processes, feedbacks and causality.
Using weather data and climate models, Annamalai found that warm sea-surface temperatures triggered atmospheric waves, shifting rainfall patterns and causing heavy rain in southwestern Pakistan, while reducing rainfall in typically wetter regions like northern India and Southeast Asia. These results indicate that the diagnostics package is performing well in determining the drivers of extreme precipitation and drought demise and can be employed to understand these events in southwestern Pakistan and other regions.
For more information, contact Clara Deck.