Roxy M. K. auteur aut IRD Ritika K. auteur aut IRD Terray Pascal auteur aut IRD Murtugudde R. auteur aut IRD Ashok K. auteur aut IRD Goswami B. N. auteur aut IRD text journalArticle eng text/pdf reformatted digital access There are large uncertainties looming over the status and fate of the South Asian summer monsoon, with several studies debating whether the monsoon is weakening or strengthening in a changing climate. Our analysis using multiple observed datasets demonstrates a significant weakening trend in summer rainfall during 1901-2012 over the central-east and northern regions of India, along the Ganges-Brahmaputra-Meghna basins and the Himalayan foothills, where agriculture is still largely rain-fed. Earlier studies have suggested an increase in moisture availability and land-sea thermal gradient in the tropics due to anthropogenic warming, favouring an increase in tropical rainfall. Here we show that the land-sea thermal gradient over South Asia has been decreasing, due to rapid warming in the Indian Ocean and a relatively subdued warming over the subcontinent. Using long-term observations and coupled model experiments, we provide compelling evidence that the enhanced Indian Ocean warming potentially weakens the land-sea thermal contrast, dampens the summer monsoon Hadley circulation, and thereby reduces the rainfall over parts of South Asia. specialized INDE OCEAN INDIEN 032 021 6 art. 7423 [10 ] 2015 2041-1723 https://www.documentation.ird.fr/hor/fdi:010065146 10.1038/ncomms8423 2041-1723 [F B010065146] https://www.documentation.ird.fr/hor/fdi:010065146 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/divers17-10/010065146.pdf IRD - Base Horizon / Pleins textes 2015-07-29 2017-10-31 fdi:010065146 fre