On the Origin of Water Masses in the Beaufort Gyre
On the Origin of Water Masses in the Beaufort Gyre
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DOI：
10.1029/2019jc015022
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发表时间：
2019-07-01
影响因子：
3.6
通讯作者：
Yool, A.
中科院分区：
文献类型：
--
作者：
Kelly, S. J.;Proshutinsky, A.;Yool, A.
波弗特环流是北冰洋的一个主要特征，是该地区淡水的蓄水池。根据北极盛行的大气环流是反气旋环流还是气旋环流，淡水要么净积累，要么释放。北冰洋的淡水来源已经确定，包括北美和欧亚河流、白令海峡太平洋水流入、海冰融化和降水，但它们对波弗特盖尔淡水积累的贡献随着大气环流的变化而不同。在这里，我们使用拉格朗日回溯跟踪技术，结合欧洲海洋模式的1/12度分辨率Nucleus模式，研究波弗特环流的淡水来源在近几十年来是如何变化的，重点是1980年代末至2000年代初环流中太平洋水含量的增加。利用经验正交函数分析了20世纪80年代至21世纪初北冰洋环流的变化。我们突出了20世纪80年代出现的等候室平流路径，并提供了证据，表明这条路径是由北极Ekman输送辐合中心的转移引起的。我们讨论了这些变化作为促成波弗特环流地区层结变化的一个因素，从而潜在地影响了生物的变化。平白的语言摘要北冰洋中顺时针方向的冰和水循环的波弗特环流是北极的一个重要特征，因为它储存了大量的淡水-相对于其他海洋-水。根据驱动它的大气环流，波弗特环流可以积累或释放这些淡水。博福特环流相对淡水的来源是北冰洋河流、白令海峡和融化的海冰。通过跟踪高分辨率海洋模型中的虚拟粒子，我们调查了近几十年来这些源是如何变化的，并确定了将它们带到波弗特环流的路径的变化。海洋环流的这种变化被发现与模式中混合层深度的变化有关。
The Beaufort Gyre is a key feature of the Arctic Ocean, acting as a reservoir for freshwater in the region. Depending on whether the prevailing atmospheric circulation in the Arctic is anticyclonic or cyclonic, either a net accumulation or release of freshwater occurs. The sources of freshwater to the Arctic Ocean are well established and include contributions from the North American and Eurasian Rivers, the Bering Strait Pacific water inflow, sea ice meltwater, and precipitation, but their contribution to the Beaufort Gyre freshwater accumulation varies with changes in the atmospheric circulation. Here we use a Lagrangian backward tracking technique in conjunction with the 1/12-degree resolution Nucleus for European Modelling of the Ocean model to investigate how sources of freshwater to the Beaufort Gyre have changed in recent decades, focusing on increase in the Pacific water content in the gyre between the late 1980s and early 2000s. Using empirical orthogonal functions we analyze the change in the Arctic oceanic circulation that occurred between the 1980s and 2000s. We highlight a waiting room advective pathway that was present in the 1980s and provide evidence that this pathway was caused by a shift in the center of Ekman transport convergence in the Arctic. We discuss the role of these changes as a contributing factor to changes in the stratification, and hence potentially the biology, of the Beaufort Gyre region.Plain Language Summary The Beaufort Gyre, a clockwise ice and water circulation in the Arctic Ocean, is an important feature of the Arctic because it stores a large volume of fresh-relative to the rest of the ocean-water. Depending on the atmospheric circulation driving it, the Beaufort Gyre can either accumulate or release this freshwater. The sources of relatively freshwater to the Beaufort Gyre are Arctic rivers, the Bering Strait, and melting sea ice. By tracking virtual particles in a high-resolution ocean model, we investigate how these sources have changed in recent decades, and identify a change in the pathways bringing them to the Beaufort Gyre. This change in ocean circulation was found to correlate with a change in the mixed layer depth in the model.