The Southern Ocean (>30° S) has taken up a large amount of anthropogenic heat north of the Subantarctic Front (SAF) of the Antarctic Circumpolar Current (ACC). Poor sampling before the 1990s and decadal variability have heretofore masked the ocean’s dynamic response to this warming. Here we use the lengthening satellite altimetry and Argo float records to show robust acceleration of zonally averaged Southern Ocean zonal flow at 48° S–58° S. This acceleration is reproduced in a hierarchy of climate models, including an ocean-eddy-resolving model. Anthropogenic ocean warming is the dominant driver, as large (small) heat gain in the downwelling (upwelling) regime north (south) of the SAF causes zonal acceleration on the northern flank of the ACC and adjacent subtropics due to increased baroclinicity; strengthened wind stress is of secondary importance. In Drake Passage, little warming occurs and the SAF velocity remains largely unchanged. Continued ocean warming could further accelerate Southern Ocean zonal flow.

南大洋（>30°S）在南极绕极流（ACC）的亚南极锋（SAF）以北吸收了大量的人为热量。迄今为止，1990 年代之前的不良采样和年代际变化掩盖了海洋对这种变暖的动态反应。在这里，我们使用加长的卫星测高仪和 Argo 浮动记录来显示南大洋纬向平均流在 48° S-58° S 处的强劲加速度。这种加速度在气候模型的层次结构中重现，包括海洋涡流解析模型. 人为海洋变暖是主要驱动因素，因为 SAF 北（南）下流（上流）区域的大（小）热增益导致由于斜压增加而导致 ACC 北翼和相邻亚热带的纬向加速；加强风应力是次要的。在德雷克海峡，几乎没有发生变暖，SAF 速度基本保持不变。持续的海洋变暖可能会进一步加速南大洋的纬向流动。