Water mass transformation in the deep basins of the Nordic Seas: Analyses of heat and freshwater budgets
Water mass transformation in the deep basins of the Nordic Seas: Analyses of heat and freshwater budgets
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DOI：
10.1016/j.dsr.2016.04.012
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发表时间：
2016-08-01
影响因子：
2.4
通讯作者：
Quadfasel, D.
中科院分区：
文献类型：
--
作者：
Latarius, K.;Quadfasel, D.
在北冰洋地中海地区，流入地表附近的大西洋水会转变为溢流水，并在深处离开该地区。对于这种转变，北欧海尤其重要，因为它们基本上不结冰，因此冬季大气中的热量损失很大。自2001年起，在该地区开展了Argo型剖面浮标测量，实现了全年水文观测。测量集中在深盆地、挪威盆地、罗弗敦盆地、格陵兰海和冰岛高原。对它们的分析特别强调水文学中的季节周期。根据本世纪头十年的温度和盐度的平均季节周期以及再分析产品的大气通量，计算了热量和淡水收支。预算中的剩余部分给出了内盆地与边界水流之间的横向水交换，环绕整个地区。这种横向交换被认为是深海盆地对北欧海域水团转化的贡献。使用 NCEP 的大气通量数据和高纬度修正的预算计算得出，尽管这些盆地仅占总面积的 4%，但北冰洋地中海地区的总气温下降贡献了 18%，总盐度下降贡献了 6%。密度增加几乎完全发生在东部盆地，而格陵兰海在匹配溢流水的温度和盐度特征方面发挥着重要作用。表层淡水数量的增加只会对格陵兰-冰岛-苏格兰海岭的溢流强度产生轻微影响。 (C) 2016 Elsevier Ltd. 保留所有权利。
In the Arctic Mediterranean a transformation of Atlantic Water, flowing in near the surface, into overflow water, which leaves the area at depth, takes place. For this transformation the Nordic Seas are of particular importance, as they are largely ice-free and thus heat loss to the atmosphere during winter is strong. Since 2001 Argo-type profiling float measurements have been carried out in the region and enable the observation of hydrography during the whole year. The measurements concentrate on the deep basins, the Norwegian Basin, Lofoten Basin, Greenland Sea and Icelandic Plateau. They are analysed with special emphasis on the seasonal cycle in hydrography. Based on the mean seasonal cycle of temperature and salinity and atmospheric fluxes from reanalysis products for the first decade of this century heat and freshwater budgets are calculated. The residuum in the budgets gives the lateral exchange of water between the inner basins and the boundary current, circumnavigating the whole area. This lateral exchange is identified with the contribution of the deep basins to the water mass transformation within the Nordic Seas. Budget calculations, using atmospheric flux data from NCEP with corrections for high latitudes, yield a contribution of 18% to the total temperature decrease and 6% to the total salinity decrease in the Arctic Mediterranean, although the basins account for only 4% of the total area. The density increase nearly exclusively takes place in the eastern basins, whereas the Greenland Sea plays an important role in matching the temperature and salinity characteristic of the overflow water. An increasing amount of freshwater in the surface layer will have only minor effects on the strength of the overflows across the Greenland-Iceland-Scotland Ridge. (C) 2016 Elsevier Ltd. All rights reserved.