美国亚利桑那大学K. Thirumalai团队研究了在最后一次冰川消融期间，极端的印度夏季风状态扼杀了孟加拉湾的生产力。2025年4月28日出版的《自然—地球科学》杂志发表了这项成果。
印度夏季季风（ISM）水文学推动了南亚和印度洋的生物地球化学循环，对地球上人口最稠密地区的粮食安全起到了一级控制作用。尽管预计在持续的温室气体胁迫下，ISM将加剧，但预计其对未来印度洋分层和初级生产的影响存在很大的不确定性，而这些过程对该地区已经衰退的渔业的健康至关重要。研究组介绍了自末次冰期（约21000年前（ka））以来孟加拉湾（BoB）ISM径流变化和海洋生物地球化学影响的世纪级记录。
这些记录揭示了相对于现代强度的极端季风状态，海因里希体育场1期的ISM强度最弱（约17.5-15.5 ka），全新世早期最强（约10.5-9.5 ka）。与直觉相反，研究组发现，由于上层海洋分层，在季风过剩和赤字的极端状态下，BoB生产力都崩溃了。该研究结果表明，在ISM制度加强和更加多变的情况下，BoB初级生产力未来有可能下降。
附：英文原文
Title: Extreme Indian summer monsoon states stifled Bay of Bengal productivity across the last deglaciation
Author: Thirumalai, K., Clemens, S. C., Rosenthal, Y., Conde, S., Bu, K., Desprat, S., Erb, M., Vetter, L., Franks, M., Cheng, J., Li, L., Liu, Z., Zhou, L. P., Giosan, L., Singh, A., Mishra, V.
Issue&Volume: 2025-04-28
Abstract: Indian summer monsoon (ISM) hydrology fuels biogeochemical cycling across South Asia and the Indian Ocean, exerting a first-order control on food security in Earth’s most densely populated areas. Although the ISM is projected to intensify under continued greenhouse forcing, substantial uncertainty surrounds anticipating its impacts on future Indian Ocean stratification and primary production—processes key to the health of already-declining fisheries in the region. Here we present century-scale records of ISM runoff variability and marine biogeochemical impacts in the Bay of Bengal (BoB) since the Last Glacial Maximum (～21 thousand years ago (ka)). These records reveal extreme monsoon states relative to modern strength, with weakest ISM intensity during Heinrich Stadial 1 (～17.5–15.5ka) and strongest during the early Holocene (～10.5–9.5ka). Counterintuitively, we find that BoB productivity collapsed during both extreme states of peak monsoon excess and deficits—both due to upper-ocean stratification. Our findings point to the possibility of future declines in BoB primary productivity under a strengthening and more variable ISM regime.
DOI: 10.1038/s41561-025-01684-6
Source: https://www.nature.com/articles/s41561-025-01684-6