20206-06-01 カリフォルニア大学サンタバーバラ校（UCSB）
Climate dynamics can be quite nuanced, with far off winds influencing tropical oceans.Photo Credit:Oporkka via iStock
＜関連情報＞
- https://news.ucsb.edu/2026/022604/distant-winds-can-drive-massive-tropical-warming-deep-below-ocean-surface
- https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G54520.1/730579/Large-mid-to-late-Holocene-warming-of-equatorial?redirectedFrom=fulltext
完新世中期から後期にかけての赤道大西洋中層水の大きな温暖化：南北循環の南側支流の役割
Large mid- to late Holocene warming of equatorial Atlantic intermediate waters: The role of the southern branch of the Meridional Overturning Circulation
Syee Weldeab
Geology Published:May 08, 2026
DOI:https://doi.org/10.1130/G54520.1
The ongoing intensification and southward shift of Southern Hemisphere westerly winds (SWWs) are dynamically involved in the downward deep-ocean transfer of excess heat arising from Earth’s radiative forcing imbalances. Yet, the process and extent of this heat transfer are poorly understood, in part due to insufficient data on analogous processes in the geologic record. I show, for the first time, an unprecedented and significant warming (5 ± 0.9 °C) of equatorial Atlantic upper intermediate waters (830 m) during the mid- to late Holocene, a period without significant increases in radiative forcing. I propose that this warming was dynamically linked to enhanced downwelling and advection of warm water equatorward of the wind stress maximum of intensified SWWs. My discovery highlights the important, yet underexplored, role of the wind-driven southern branch of the Meridional Overturning Circulation in redistributing heat to the tropical oceans. More broadly, my observations serve as an analogue, demonstrating the important role tropical upper intermediate waters may play in sequestering excess heat under ongoing global warming.
