Influence of Enhanced Abyssal Diapycnal Mixing on Stratification and the Ocean Overturning Circulation
Influence of Enhanced Abyssal Diapycnal Mixing on Stratification and the Ocean Overturning Circulation
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DOI：
10.1175/jpo-d-15-0039.1
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发表时间：
2015-10
影响因子：
3.5
通讯作者：
A. Mashayek;R. Ferrari;M. Nikurashin;W. Peltier
中科院分区：
文献类型：
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作者：
A. Mashayek;R. Ferrari;M. Nikurashin;W. Peltier
经向翻转环流(MOC)是由相互连接的翻转环流构成的，它将在高纬度形成的致密的冷水带回地表。湍流昼夜混合在决定构成MOC的各种翻转单体的速率和模式方面起着主要作用。本文分析的重点将是混合的急剧垂直变化对MOC和海洋层化的影响。混合在海底地形附近增强，在那里潮汐和地转运动与地形相互作用产生的内波破裂。结果表明，混合的剧烈垂直变化导致了三层结构的形成，它们控制着经向流动的不同动态平衡。具体地说，在混合最大的海底上方形成了一个深海底部边界层，将最重的水从南部航道向北输送到封闭的盆地。在海床上方形成了一层深层。
AbstractThe meridional overturning circulation (MOC) is composed of interconnected overturning cells that transport cold dense abyssal waters formed at high latitudes back to the surface. Turbulent diapycnal mixing plays a primary role in setting the rate and patterns of the various overturning cells that constitute the MOC. The focus of the analyses in this paper will be on the influence of sharp vertical variations in mixing on the MOC and ocean stratification. Mixing is enhanced close to the ocean bottom topography where internal waves generated by the interaction of tides and geostrophic motions with topography break. It is shown that the sharp vertical variations in mixing lead to the formation of three layers with different dynamical balances governing meridional flow. Specifically, an abyssal bottom boundary layer forms above the ocean floor where mixing is largest and hosts the northward transport of the heaviest waters from the southern channel to the closed basins. A deep layer forms above the b...