How Much Arctic Fresh Water Participates in the Subpolar Overturning Circulation?
How Much Arctic Fresh Water Participates in the Subpolar Overturning Circulation?
复制标题
有多少北极淡水参与了副极地翻转环流？
DOI：
10.1175/jpo-d-20-0240.1
复制
发表时间：
2021
影响因子：
3.5
通讯作者：
Holliday, N. Penny
中科院分区：
文献类型：
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作者：
Le Bras, Isabela;Straneo, Fiamma;Muilwijk, Morven;Smedsrud, Lars H.;Li, Feili;Lozier, M. Susan;Holliday, N. Penny
流入大西洋的新鲜北极沃茨被认为有两个主要的命运。它们可能作为翻转环流的一部分混入深海，或沿着深水形成区域流动而不影响翻转。气候模型表明，随着越来越多的淡水进入大西洋，翻转环流将被破坏，但我们缺乏对当今有多少淡水混入翻转环流的深支的了解。为了限制这些淡水途径，我们建立了稳态体积，盐，热预算格陵兰岛东部的初始化与观测和封闭使用逆方法。淡水资源被分为海洋极地沃茨从北极和地表淡水通量，其中包括净降水，径流和冰融化，以研究他们如何不同的印记循环。我们发现进入我们区域的110 mSv地表淡水通量中有65 mSv（1 Sv <$106 m3 s −1）参与了翻转环流，流经弗拉姆海峡的1.2 Sv极地沃茨中有0.6 Sv也参与了翻转环流。基于这些结果，我们假设翻转环流对未来北极淡水流出和降水的变化更敏感，而格陵兰径流和冰山融化更有可能沿着格陵兰海岸。
Fresh Arctic waters flowing into the Atlantic are thought to have two primary fates. They may be mixed into the deep ocean as part of the overturning circulation, or flow alongside regions of deep water formation without impacting overturning. Climate models suggest that as increasing amounts of freshwater enter the Atlantic, the overturning circulation will be disrupted, yet we lack an understanding of how much freshwater is mixed into the overturning circulation’s deep limb in the present day. To constrain these freshwater pathways, we build steady-state volume, salt, and heat budgets east of Greenland that are initialized with observations and closed using inverse methods. Freshwater sources are split into oceanic Polar Waters from the Arctic and surface freshwater fluxes, which include net precipitation, runoff, and ice melt, to examine how they imprint the circulation differently. We find that 65 mSv (1 Sv ≡ 106m3s−1) of the total 110 mSv of surface freshwater fluxes that enter our domain participate in the overturning circulation, as do 0.6 Sv of the total 1.2 Sv of Polar Waters that flow through Fram Strait. Based on these results, we hypothesize that the overturning circulation is more sensitive to future changes in Arctic freshwater outflow and precipitation, while Greenland runoff and iceberg melt are more likely to stay along the coast of Greenland.