近日，美国纽约城市大学Spencer A. Hill团队揭示了厄尔尼诺夏季印度季风降雨更极端。该研究于2025年9月18日发表在《科学》杂志上。
印度夏季季风期间的极端降雨对这个世界第三大经济体和人口最多的国家造成破坏性和致命性的影响。
虽然已知赤道太平洋的厄尔尼诺现象抑制了整个印度的夏季总降雨量，但研究组使用1901~2020年的观测数据表明，与直觉相反，它们同时加剧了极端日降雨量。该现象部分归因于对流浮力的极端日值增加，前提是考虑到近地面空气的未稀释不稳定性以及与上层干燥空气混合而产生的稀释。厄尔尼诺可能会在其他热带地区引发类似的变化，该框架可进一步应用于每小时极值的变化、其他内部变率模式，以及气候变化驱动的强迫趋势。
附：英文原文
Title: More extreme Indian monsoon rainfall in El Nio summers
Author: Spencer A. Hill, Destiny Zamir Meyers, Adam H. Sobel, Michela Biasutti, Mark A. Cane, Michael K. Tippett, Fiaz Ahmed
Issue&Volume: 2025-09-18
Abstract: Extreme rainfall during the Indian summer monsoon can be destructive and deadly to the world’s third-largest economy and most populous country. Although El Nio events in the equatorial Pacific are known to suppress total summer rainfall throughout India, we show using observational data spanning 1901 to 2020 that, counterintuitively, they simultaneously intensify extreme daily rainfall. This is partly driven by increases in extreme daily values of convective buoyancy, provided that both the undilute instability of near-surface air and the dilution by mixing with drier air above are considered. El Nio could plausibly drive similar changes in other tropical regions, and our framework could be further applied to changes in hourly extremes, to other internal variability modes, and to forced trends under climate change.
DOI: adg5577