Atlantic Water flow through the Barents and Kara Seas
Atlantic Water flow through the Barents and Kara Seas
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DOI：
10.1016/s0967-0637(02)00125-5
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发表时间：
2002-12-01
影响因子：
2.4
通讯作者：
Dieck, W
中科院分区：
文献类型：
--
作者：
Schauer, U;Loeng, H;Dieck, W
20世纪90年代的水文测量和洋流测量记录了挪威海穿过巴伦支海并通过圣安娜海槽的水的路径和转变。通过巴伦支海东北部一系列系泊的输送量在夏季为0.6 Sv，冬季为2.6 Sv，向喀拉海输送量在0至0.3 Sv之间，平均净流量为1.5 Sv。向西流起源于欧亚大陆斜坡上大西洋水域的弗拉姆海峡分支，而向东流构成巴伦支海分支，从巴伦支海西部开口继续。大约75%的东进气流低于0度。气流被强烈剪切，最高速度接近底部。全年温度几乎恒定在-0.5℃左右的深层形成了大约50%的喀拉海水流。这种水是温暖的大西洋盐水和寒冷的富含盐水的水的混合物，这些水是在新地岛以西的多冰湖（可能也在中央银行）通过冻结和对流产生的。它的盐度低于大西洋水在巴伦支海入口处的盐度，因为冰的形成发生在低盐度的表层。释放出来的盐水增加了表层的盐度和密度，足以使其对流，但不一定高于大西洋水的盐度。新地岛以西的淡水主要来自大陆径流，而中央银行的淡水可能来自冰川融化。淡水的数量与西巴伦支海陆地淡水供应量的22%相比。深层在没有进一步变化的情况下继续进入喀拉海，并在温暖、含盐的弗拉姆海峡分支的核心深度或以下进入南森盆地。因为它的温度低于0摄氏度，所以它不会被称为北冰洋中的大西洋水。在早期的几十年里，从弗拉姆海峡平流过来的大西洋水比20世纪90年代冷了近2 K，而稠密的巴伦支海水只在底部的薄层中冷了1 K，盐度变化很大。然而，随着密度的增加，欧亚盆地深处的水性质直到20世纪70年代才得到满足。1980年大盐度异常的极低盐度在流出资料中未被发现。我们得出结论，巴伦支海大西洋海水的热变率受到抑制，而盐度变化则通过淡水条件和新地岛对流区冰的增长而得到强烈的改变。(C) 2002 Elsevier Science Ltd.版权所有。
The pathway and transformation of water from the Norwegian Sea across the Barents Sea and through the St. Anna Trough are documented from hydrographic and current measurements of the 1990s. The transport through an array of moorings in the north-eastern Barents Sea was between 0.6 Sv in summer and 2.6 Sv in winter towards the Kara Sea and between zero and 0.3 Sv towards the Barents Sea with a record mean net flow of 1.5 Sv. The westward flow originates in the Fram Strait branch of Atlantic Water at the Eurasian continental slope, while the eastward flow constitutes the Barents Sea branch, continuing from the western Barents Sea opening.About 75% of the eastward flow was colder than 0degreesC. The flow was strongly sheared, with the highest velocities close to the bottom. A deep layer with almost constant temperature of about -0.5degreesC throughout the year formed about 50% of the flow to the Kara Sea. This water was a mixture between warm saline Atlantic Water and cold, brine-enriched water generated through freezing and convection in polynyas west of Novaya Zemlya, and possibly also at the Central Bank. Its salinity is lower than that of the Atlantic Water at its entrance to the Barents Sea, because the ice formation occurs in a low salinity surface layer. The released brine increases the salinity and density of the surface layer sufficiently for it to convect, but not necessarily above the salinity of the Atlantic Water. The freshwater west of Novaya Zemlya primarily stems from continental runoff and at the Central Bank probably from ice melt. The amount of fresh water compares to about 22% of the terrestrial freshwater supply to the western Barents Sea. The deep layer continues to the Kara Sea without further change and enters the Nansen Basin at or below the core depth of the warm, saline Fram Strait branch. Because it is colder than 0degreesC it will not be addressed as Atlantic Water in the Arctic Ocean.In earlier decades, the Atlantic Water advected from Fram Strait was colder by almost 2 K as compared to the 1990s, while the dense Barents Sea water was colder by up to 1 K only in a thin layer at the bottom and the salinity varied significantly. However, also with the resulting higher densities, deep Eurasian Basin water properties were met only in the 1970s. The very low salinities of the Great Salinity Anomaly in 1980 were not discovered in the outflow data. We conclude that the thermal variability of inflowing Atlantic water is damped in the Barents Sea, while the salinity variation is strongly modified through the freshwater conditions and ice growth in the convective area off Novaya Zemlya. (C) 2002 Elsevier Science Ltd. All rights reserved.