Atlantic Deep Water Formation Occurs Primarily in the Iceland Basin and Irminger Sea by Local Buoyancy Forcing
Atlantic Deep Water Formation Occurs Primarily in the Iceland Basin and Irminger Sea by Local Buoyancy Forcing
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DOI：
10.1029/2020gl091028
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发表时间：
2020-11-28
影响因子：
5.2
通讯作者：
Cunningham, Stuart A.
中科院分区：
文献类型：
--
作者：
Petit, Tillys;Lozier, M. Susan;Cunningham, Stuart A.
大西洋经向翻转环流是气候系统中的一个关键机制，它将温暖和咸沃茨从副热带环流输送到副极地环流和北欧海，在那里它们被转化为密度更大的沃茨，在大西洋经向翻转环流的下边缘向南流动。流行的假设是，密集的沃茨形成的拉布拉多和北欧海的来源AMOC下肢。然而，最近的观测表明，拉布拉多海的对流对副极地环流的总翻转贡献最小。在这项研究中，我们表明，AMOC，而不是主要由沃茨形成的北欧海和Irminger和冰岛盆地。这些盆地的热量和淡水通量的第一个直接估计表明，浮力强迫在冬季的几个月几乎可以完全占密集的沃茨的亚极地北大西洋出口的一部分AMOC。
The Atlantic Meridional Overturning Circulation (AMOC), a key mechanism in the climate system, delivers warm and salty waters from the subtropical gyre to the subpolar gyre and Nordic Seas, where they are transformed into denser waters flowing southward in the lower AMOC limb. The prevailing hypothesis is that dense waters formed in the Labrador and Nordic Seas are the sources for the AMOC lower limb. However, recent observations reveal that convection in the Labrador Sea contributes minimally to the total overturning of the subpolar gyre. In this study, we show that the AMOC is instead primarily composed of waters formed in the Nordic Seas and Irminger and Iceland basins. A first direct estimate of heat and freshwater fluxes over these basins demonstrates that buoyancy forcing during the winter months can almost wholly account for the dense waters of the subpolar North Atlantic that are exported as part of the AMOC.