Wang Hailin, Qiu Bo, Liu Hanrui, Zhang Zhengguang
Frontiers Science Center for Deep Ocean Multispheres and Earth System (FDOMES) and Key Laboratory of Physical Oceanography, Academy of the Future Ocean, Chongben Honors College, Ocean University of China, Qingdao, PR China.
Department of Oceanography, University of Hawaii at Manoa, Honolulu, HI, USA.
Nat Commun. 2023 Sep 6;14(1):5460. doi: 10.1038/s41467-023-41294-7.
Oceanic transport of heat by ubiquitous mesoscale eddies plays a critical role in regulating climate variability and redistributing excess heat absorbed by ocean under global warming. Eddies have long been simplified as axisymmetric vortices and their influence on heat transport remains unclear. Here, we combine satellite and drifter data and show that oceanic mesoscale eddies are asymmetric and directionally-dependent, and are controlled by their self-sustaining nature and their dynamical environment. Both the direction and amplitude of eddy-induced heat fluxes are significantly influenced by eddy's asymmetry and directional dependence. When the eddy velocity field is decomposed into asymmetric and symmetric components, the eddy kinetic energy exhibits a nearly equal partition between these two components. The total eddy-induced meridional heat flux similarly doubles the heat flux induced by the symmetric components, highlighting the crucial contribution of eddy asymmetry on the magnitude of eddy-induced oceanic heat transport.
无处不在的中尺度涡旋对热量的海洋输送在调节气候变率以及在全球变暖情况下重新分配海洋吸收的多余热量方面起着关键作用。长期以来，涡旋一直被简化为轴对称涡旋，其对热量输送的影响仍不明确。在此，我们结合卫星和漂流浮标数据表明，海洋中尺度涡旋是不对称且具有方向依赖性的，并且受其自我维持特性及其动力环境的控制。涡旋诱导热通量的方向和幅度均受到涡旋不对称性和方向依赖性的显著影响。当涡旋速度场分解为不对称和对称分量时，涡旋动能在这两个分量之间呈现近乎相等的分配。总的涡旋诱导经向热通量同样是对称分量诱导热通量的两倍，这突出了涡旋不对称性对涡旋诱导海洋热量输送量级的关键贡献。
