Emerging human-induced changes in the Southern Hemisphere ocean surface winds
摘要
Ocean surface wind changes regulate air–sea exchanges of momentum, buoyancy, and gases, with far‑reaching implications for the climate system. Although human influences on Southern Hemisphere winds are established from models, their detection and attribution in observations remain uncertain. Here, by applying a fingerprint‑based detection method to satellite observations and single‑forcing climate simulations, we show that an anthropogenic signal in Southern Hemisphere annual-mean surface wind speed (SWS) has emerged in the observational record. This signal is primarily associated with a poleward shift of the midlatitude SWS pattern, which is detectable since around 2016 across five observational datasets, rather than with an intensification of tropical winds. By 2016, single-forcing simulations attribute 80% of the simulated poleward shift to greenhouse gas forcing. This anthropogenic shift in SWS explains 31% of the observed increase in mechanical energy input to the Southern Ocean by wind work. Our findings demonstrate that human‑caused changes in Southern Ocean surface winds are already altering oceanic energy transfer, with further impacts anticipated as greenhouse gas emissions contiguously increase.