Forcing of the overturning circulation across a circumpolar channel by internal wave breaking
Forcing of the overturning circulation across a circumpolar channel by internal wave breaking
复制标题
DOI：
10.1002/2015jc011597
复制
发表时间：
2016-08
影响因子：
--
通讯作者：
M. B. Broadbridge;A. N. Garabato;A. Nurser
中科院分区：
文献类型：
--
作者：
M. B. Broadbridge;A. N. Garabato;A. Nurser
假设中尺度涡流对小尺度地形的冲击调节了南大洋深处的昼夜混合和经向翻转，这一假说在一个理想化的模式中得到了评估。该模式模拟了与南大洋环流性质大致相似的双单体经向翻转耦合的绕极涡流，并使用基于波辐射理论的在线公式描述了背风波诱导的昼夜混合。模拟涡场产生的昼夜混合对模式中低空翻转单体的维持起主要作用，并支持该单体对风强迫的显著敏感性。低层翻转的垂直结构是由中尺度涡旋决定的，它通过垂直移动等薄线来传播近底层日平均混合的影响。
The hypothesis that the impingement of mesoscale eddy flows on small-scale topography regulates diapycnal mixing and meridional overturning across the deep Southern Ocean is assessed in an idealised model. The model simulates an eddying circumpolar current coupled to a double-celled meridional overturning with properties broadly resembling those of the Southern Ocean circulation, and represents lee wave-induced diapycnal mixing using an online formulation grounded on wave radiation theory. The diapycnal mixing generated by the simulated eddy field is found to play a major role in sustaining the lower overturning cell in the model, and to underpin a significant sensitivity of this cell to wind forcing. The vertical structure of lower overturning is set by mesoscale eddies, which propagate the effects of near-bottom diapycnal mixing by displacing isopycnals vertically.