Fu Yao, Li Feili, Karstensen Johannes, Wang Chunzai
State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China.
Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China.
Sci Adv. 2020 Nov 27;6(48). doi: 10.1126/sciadv.abc7836. Print 2020 Nov.
The Atlantic Meridional Overturning Circulation (AMOC) is crucially important to global climate. Model simulations suggest that the AMOC may have been weakening over decades. However, existing array-based AMOC observations are not long enough to capture multidecadal changes. Here, we use repeated hydrographic sections in the subtropical and subpolar North Atlantic, combined with an inverse model constrained using satellite altimetry, to jointly analyze AMOC and hydrographic changes over the past three decades. We show that the AMOC state in the past decade is not distinctly different from that in the 1990s in the North Atlantic, with a remarkably stable partition of the subpolar overturning occurring prominently in the eastern basins rather than in the Labrador Sea. In contrast, profound hydrographic and oxygen changes, particularly in the subpolar North Atlantic, are observed over the same period, suggesting a much higher decoupling between the AMOC and ocean interior property fields than previously thought.
大西洋经向翻转环流（AMOC）对全球气候至关重要。模型模拟表明，几十年来AMOC可能一直在减弱。然而，现有的基于阵列的AMOC观测时间不够长，无法捕捉到年代际变化。在此，我们利用北大西洋亚热带和亚极地的重复水文剖面，结合使用卫星测高约束的反演模型，共同分析过去三十年中AMOC和水文变化。我们表明，过去十年北大西洋的AMOC状态与20世纪90年代没有明显差异，亚极地翻转的显著稳定划分主要发生在东部盆地而非拉布拉多海。相比之下，同期观测到了深刻的水文和氧气变化，特别是在北大西洋亚极地地区，这表明AMOC与海洋内部属性场之间的解耦程度比之前认为的要高得多。
