Jing Zhao, Wang Shengpeng, Wu Lixin, Chang Ping, Zhang Qiuying, Sun Bingrong, Ma Xiaohui, Qiu Bo, Small Justing, Jin Fei-Fei, Chen Zhaohui, Gan Bolan, Yang Yun, Yang Haiyuan, Wan Xiuquan
Key Laboratory of Physical Oceanography and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, China.
Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.
Sci Adv. 2020 Jul 31;6(31):eaba7880. doi: 10.1126/sciadv.aba7880. eCollection 2020 Jul.
Oceanic fronts associated with strong western boundary current extensions vent a vast amount of heat into the atmosphere, anchoring mid-latitude storm tracks and facilitating ocean carbon sequestration. However, it remains unclear how the surface heat reservoir is replenished by ocean processes to sustain the atmospheric heat uptake. Using high-resolution climate simulations, we find that the vertical heat transport by ocean mesoscale eddies acts as an important heat supplier to the surface ocean in frontal regions. This vertical eddy heat transport is not accounted for by the prevailing inviscid and adiabatic ocean dynamical theories such as baroclinic instability and frontogenesis but is tightly related to the atmospheric forcing. Strong surface cooling associated with intense winds in winter promotes turbulent mixing in the mixed layer, destructing the vertical shear of mesoscale eddies. The restoring of vertical shear induces an ageostrophic secondary circulation transporting heat from the subsurface to surface ocean.
与强劲的西边界流延伸相关的海洋锋面将大量热量释放到大气中，确定了中纬度风暴路径并促进了海洋碳固存。然而，目前尚不清楚海洋过程如何补充表层热库以维持大气对热量的吸收。通过高分辨率气候模拟，我们发现海洋中尺度涡旋的垂直热输送是锋面区域表层海洋的重要热量供应源。这种垂直涡旋热输送并未被诸如斜压不稳定和锋生等普遍的无粘和绝热海洋动力学理论所解释，但与大气强迫密切相关。冬季与强风相关的强烈表面冷却促进了混合层中的湍流混合，破坏了中尺度涡旋的垂直切变。垂直切变的恢复引发了一个非地转次级环流，将热量从次表层输送到表层海洋。
