Boundary Upwelling of Antarctic Bottom Water by Topographic Turbulence
Boundary Upwelling of Antarctic Bottom Water by Topographic Turbulence
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地形湍流引起的南极底层水边界上升流
DOI：
10.1029/2022av000858
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发表时间：
2023
期刊：
影响因子：
8.4
通讯作者：
Baker L
中科院分区：
文献类型：
--
作者：
Baker L
南半球翻转环流（MOC）的低层环流来源于密集的南极底层沃茨（AABW），这些海水在南极周围形成和下沉，随后填充深海。为了使主运行中心“倾覆”，这些稠密的沃茨必须通过与上面较轻的沃茨混合而上升。在这里，我们调查的过程支撑这种混合，以及由此产生的水团转换，使用观测强迫，高分辨率数值模型的德雷克海峡在南大洋。在德雷克海峡，密集的AABW形成在威德尔海与较轻的深沃茨从太平洋运输的南极绕极流的混合是催化的高能流冲击粗糙的地形。我们发现，多种地形相互作用过程促进了两种水团的混合，最终导致中性密度大于28.19 kg m−3的沃茨的上升流，以及上面较轻的沃茨的下降流。特别是，我们确定的作用，AABW和覆盖沃茨之间的尖锐的密度接口，并发现接口的动态与地形的相互作用可以修改许多过程中产生的混合。在全球海洋的几个地方已经观察到水团之间的这种尖锐界面，但在气候尺度海洋模型中没有得到解决和代表。我们认为，它们可能在深海动力学和混合中发挥重要作用，因此需要进一步探索。
The lower cell of the meridional overturning circulation (MOC) is sourced by dense Antarctic Bottom Waters (AABWs), which form and sink around Antarctica and subsequently fill the abyssal ocean. For the MOC to “overturn,” these dense waters must upwell via mixing with lighter waters above. Here, we investigate the processes underpinning such mixing, and the resulting water mass transformation, using an observationally forced, high‐resolution numerical model of the Drake Passage in the Southern Ocean. In the Drake Passage, the mixing of dense AABW formed in the Weddell Sea with lighter deep waters transported from the Pacific Ocean by the Antarctic Circumpolar Current is catalyzed by energetic flows impinging on rough topography. We find that multiple topographic interaction processes facilitate the mixing of the two water masses, ultimately resulting in the upwelling of waters with neutral density greater than 28.19 kg m−3, and the downwelling of the lighter waters above. In particular, we identify the role of sharp density interfaces between AABW and overlying waters and find that the dynamics of the interfaces' interaction with topography can modify many of the processes that generate mixing. Such sharp interfaces between water masses have been observed in several parts of the global ocean, but are unresolved and unrepresented in climate‐scale ocean models. We suggest that they are likely to play an important role in abyssal dynamics and mixing, and therefore require further exploration.
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影响因子：
5.2
作者：
L. Cimoli;Colm‐cille P. Caulfield;H. Johnson;D. Marshall;A. Mashayek;A. N. Naveira Garabato;C. Vic
通讯作者：
L. Cimoli;Colm‐cille P. Caulfield;H. Johnson;D. Marshall;A. Mashayek;A. N. Naveira Garabato;C. Vic
影响因子：
3.2
作者：
S. Legg;R. Hallberg;J. Girton
通讯作者：
S. Legg;R. Hallberg;J. Girton
影响因子：
5.2
作者：
A. Mashayek;N. Reynard;F. Zhai;K. Srinivasan;Adam Jelley;A. N. Garabato;Colm‐cille P. Caulfield
通讯作者：
Colm‐cille P. Caulfield
影响因子：
16.6
作者：
Su Z;Wang J;Klein P;Thompson AF;Menemenlis D
通讯作者：
Menemenlis D
影响因子：
3.5
作者：
J. Cusack;A. N. Garabato;D. Smeed;J. Girton
通讯作者：
J. Cusack;A. N. Garabato;D. Smeed;J. Girton