Ocean circulation causes the largest freshening event for 120 years in eastern subpolar North Atlantic
Ocean circulation causes the largest freshening event for 120 years in eastern subpolar North Atlantic
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DOI：
10.1038/s41467-020-14474-y
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发表时间：
2020-01-29
影响因子：
16.6
通讯作者：
Yashayaev, Igor
中科院分区：
文献类型：
--
作者：
Holliday, N. Penny;Bersch, Manfred;Yashayaev, Igor
大西洋翻转环流对气候系统很重要，因为它向北携带热量和碳，从海洋表面到海洋深处。北大西洋近极地的高盐度是翻转环流的先决条件，而强烈的新鲜化可能预示着环流的减缓。我们发现，在2012年至2016年期间，北大西洋亚极地东部经历了极端的清新，其强度在120年的测量中从未见过。原因是不寻常的冬季风模式导致了海洋环流的重大变化，包括北大西洋洋流的减缓和北极淡水从西部边界转移到东部盆地。我们发现，来自北极的淡水的风驱动路线与西北大西洋大陆架和斜坡区与东部次极地盆地的条件密切相关。这揭示了盆地内环流的大气强迫在确定北大西洋亚极盐度中的重要性。
The Atlantic Ocean overturning circulation is important to the climate system because it carries heat and carbon northward, and from the surface to the deep ocean. The high salinity of the subpolar North Atlantic is a prerequisite for overturning circulation, and strong freshening could herald a slowdown. We show that the eastern subpolar North Atlantic underwent extreme freshening during 2012 to 2016, with a magnitude never seen before in 120 years of measurements. The cause was unusual winter wind patterns driving major changes in ocean circulation, including slowing of the North Atlantic Current and diversion of Arctic freshwater from the western boundary into the eastern basins. We find that wind-driven routing of Arctic-origin freshwater intimately links conditions on the North West Atlantic shelf and slope region with the eastern subpolar basins. This reveals the importance of atmospheric forcing of intra-basin circulation in determining the salinity of the subpolar North Atlantic.