Slantwise Convection in the Irminger Sea
Slantwise Convection in the Irminger Sea
复制标题
伊尔明格海的倾斜对流
DOI：
10.1029/2022jc019071
复制
发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Johnson, H. L.
中科院分区：
文献类型：
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作者：
Le Bras, I. A. ‐A.;Callies, J.;Straneo, F.;Biló, T. C.;Holte, J.;Johnson, H. L.
北大西洋副极地是与大气进行大量二氧化碳、氧气和热交换的场所。这种交换调节短暂的气候变化并防止整个北大西洋的大规模缺氧，被认为是由海洋表面混合层的垂直混合介导的。在这里，我们提供了观测证据，表明比传统定义的混合层更深的水域直接受到该地区大气强迫的影响。当北风沿着伊尔明格海的西边界流吹时，埃克曼响应将密度较大的水推到密度较小的水上，可能引发倾斜对流。我们估计，这种向下的风力强迫比空气-海洋热通量浮力强迫强四倍，并且可以将水混合到传统定义的混合层深度的几倍。大多数大型海洋模型不包含倾斜对流，这可能限制了它们准确表示副极地水体转变和深海通风的能力。
The subpolar North Atlantic is a site of significant carbon dioxide, oxygen, and heat exchange with the atmosphere. This exchange, which regulates transient climate change and prevents large‐scale hypoxia throughout the North Atlantic, is thought to be mediated by vertical mixing in the ocean's surface mixed layer. Here we present observational evidence that waters deeper than the conventionally defined mixed layer are affected directly by atmospheric forcing in this region. When northerly winds blow along the Irminger Sea's western boundary current, the Ekman response pushes denser water over lighter water, potentially triggering slantwise convection. We estimate that this down‐front wind forcing is four times stronger than air–sea heat flux buoyancy forcing and can mix waters to several times the conventionally defined mixed layer depth. Slantwise convection is not included in most large‐scale ocean models, which likely limits their ability to accurately represent subpolar water mass transformations and deep ocean ventilation.