In the early spring of 2022, South Asian countries together with India, Pakistan, and Afghanistan skilled back-to-back excessive warmth waves in the months of March and April.
A research printed on April 8, 2025, by researchers from the Indian Institute of Technology (IIT) Bombay and Johannes Gutenberg-University Mainz, Germany, has uncovered why South Asian international locations skilled back-to-back excessive warmth occasions in early spring of 2022.
Also learn: Why is north and central India dealing with a extreme heatwave? | Explained
In the research titled, ‘Contrasting drivers of consecutive pre-monsoon South Asian heatwaves in 2022: waveguide interaction and soil moisture depletion’ printed in Journal of Geophysical Research: Atmospheres, a scientific journal of atmospheric analysis printed by the American Geophysical Union; the analysis staff discovered that these unusually intense heatwave occasions in March and April of 2022, had been pushed by completely different atmospheric processes that compounded heatwave impacts.
Lead creator of the research, Roshan Jha, a PhD pupil at Centre for Climate Studies, IIT Bombay, stated, “Our analysis shows that the March heatwave was primarily linked to a sudden increase in the amplitude of short-lived atmospheric Rossby waves, which are large-scale meanders in high altitude winds resembling bends in a winding river. The waves grew stronger as high-altitude westerly winds near the poles (extratropical jet stream) transferred energy to westerly winds closer to the equator (subtropical jet stream) as they came closer during the heatwave.”
The April heatwave occurred otherwise as in, as a substitute of being pushed by wind patterns in excessive altitude, it was largely caused by very dry soil conditions and advection of warmth to India from north-western land areas of Pakistan and Afghanistan. Co-author of the research, Arpita Mondal, Associate Professor in the Department of Civil Engineering and Centre for Climate Studies at IIT Bombay defined that importantly, these dry conditions had been partly created by the sooner March heatwave, which had already dried out the land by means of excessive temperatures and clear skies.
“This research reveals a concerning pattern: one heatwave can set the stage for another, more intense heat event in the following weeks by removing moisture from the soil. When soil becomes too dry, it creates a cycle that makes the next heatwave even worse. When soil has moisture, under the clear sky conditions, some of the sun’s energy goes into evaporating that moisture rather than heating the air. But when the soil is already dry, all that energy goes straight into making the air hotter,” she defined.
Subimal Ghosh, Convener of Centre for Climate Studies, IIT Bombay and Professor at Department of Civil Engineering, IIT Bombay stated that understanding these mechanisms is essential for enhancing our capability to forecast and put together for excessive warmth occasions in South Asia. “As climate change continues to affect atmospheric wind patterns, identifying these specific drivers helps us better predict and mitigate the impacts of future heatwaves,” he added.
The different co-authors are Professor Volkmar Wirth and Dr. Christopher Polster from Institute for Atmospheric Physics at Johannes Gutenberg-University Mainz, Germany.
Published – April 16, 2025 10:01 am IST
