拉布拉多海变清新与波弗特环流释放淡水有关。

Labrador Sea freshening linked to Beaufort Gyre freshwater release.

机构信息

Computational Physics and Methods, Los Alamos National Laboratory, Los Alamos, NM, USA.

Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, NM, USA.

出版信息

Nat Commun. 2021 Feb 23;12(1):1229. doi: 10.1038/s41467-021-21470-3.

DOI:10.1038/s41467-021-21470-3

PMID:33623045

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC7902633/

Abstract

The Beaufort Gyre (BG), the largest Arctic Ocean freshwater reservoir, has drastically increased its liquid freshwater content by 40% in the past two decades. If released within a short period, the excess freshwater could potentially impact the large-scale ocean circulation by freshening the upper subpolar North Atlantic. Here, we track BG-sourced freshwater using passive tracers in a global ocean sea-ice model and show that this freshwater exited the Arctic mostly through the Canadian Arctic Archipelago, rather than Fram Strait, during an historical release event in 1983-1995. The Labrador Sea is the most affected region in the subpolar North Atlantic, with a freshening of 0.2 psu on the western shelves and 0.4 psu in the Labrador Current. Given that the present BG freshwater content anomaly is twice the historical analog studied here, the impact of a future rapid release on Labrador Sea salinity could be significant, easily exceeding similar fluxes from Greenland meltwater.

摘要

比弗福特旋迴（BG）是北冰洋最大的淡水储存库，在过去二十年中其液态淡水含量大幅增加了 40%。如果在短时间内释放，过多的淡水可能会通过使上亚北极北大西洋变轻而影响大规模海洋环流。在这里，我们使用被动示踪剂在一个全球海洋海冰模型中追踪 BG 来源的淡水，并表明在 1983-1995 年的一次历史释放事件中，这些淡水主要通过加拿大北极群岛而不是弗拉姆海峡离开北极。拉布拉多海是亚北极北大西洋受影响最严重的地区，西部陆架的盐度降低了 0.2 个 PSU，拉布拉多海流降低了 0.4 个 PSU。鉴于目前 BG 淡水含量异常是这里研究的历史类似物的两倍，未来快速释放对拉布拉多海盐度的影响可能是巨大的，轻易超过来自格陵兰融水的类似通量。