Recent state transition of the Arctic Ocean’s Beaufort Gyre
Recent state transition of the Arctic Ocean’s Beaufort Gyre
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DOI：
10.1038/s41561-023-01184-5
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发表时间：
2023-05
影响因子：
18.3
通讯作者：
Peigen Lin;R. Pickart;H. Heorton;M. Tsamados;M. Itoh;T. Kikuchi
中科院分区：
文献类型：
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作者：
Peigen Lin;R. Pickart;H. Heorton;M. Tsamados;M. Itoh;T. Kikuchi
反气旋波弗特环流是加拿大盆地的主导环流，也是北冰洋最大的淡水水库。 2000年代初期，环流加强、扩大并积聚淡水。利用2003年至2019年的广泛水文数据集，再加上更新的卫星动态海洋地形数据，我们发现，在过去十年中，波弗特环流已过渡到准稳定状态，其中环流海面高度的增长放缓，淡水含量趋于稳定。此外，由于来自太平洋和楚科奇海陆架的冷水和咸水输入减少，以及来自波弗特海东部的较轻水的夹带增多，隔离大西洋深处暖/咸水的冷盐跃层已显着变薄。波弗特环流最近的转变与其位置向东南的移动有关，这是由于区域风力强迫的变化造成的。我们的结果表明，冷盐斜层的持续变薄可以调节目前的稳定状态，从而允许淡水释放。反过来，这可能会使北大西洋副极地变得清新，影响大西洋经向翻转环流。
The anti-cyclonic Beaufort Gyre is the dominant circulation of the Canada Basin and the largest freshwater reservoir in the Arctic Ocean. During the first part of the 2000s, the gyre intensified, expanded and accumulated freshwater. Using an extensive hydrographic dataset from 2003 to 2019, together with updated satellite dynamic ocean topography data, we find that over the past decade the Beaufort Gyre has transitioned to a quasi-stable state in which the increase in sea surface height of the gyre has slowed and the freshwater content has plateaued. In addition, the cold halocline layer, which isolates the warm/salty Atlantic water at depth, has thinned significantly due to less input of cold and salty water stemming from the Pacific Ocean and the Chukchi Sea shelf, together with greater entrainment of lighter water from the eastern Beaufort Sea. This recent transition of the Beaufort Gyre is associated with a southeastward shift in its location as a result of variation in the regional wind forcing. Our results imply that continued thinning of the cold halocline layer could modulate the present stable state, allowing for a freshwater release. This, in turn, could freshen the subpolar North Atlantic, impacting the Atlantic Meridional Overturning Circulation.