与全球变暖相反，整个20世纪，次极地北大西洋经历了长期的降温。这种冷却被称为北大西洋冷团，被认为是由于与大西洋经向翻转环流（AMOC）减缓相关的极地海洋热输送减少造成的。
通过诊断来自多个耦合气候模型的历史模拟，研究组发现海洋热传输并不是AMOC调节海面温度变化的唯一途径。AMOC减弱也与较冷、较干燥的低层大气条件有关，这导致地表变暖减少，这是由于减少了地表向下的晴空长波辐射，从而增加了吸热气体的量。这种辐射路径和海洋过程对北大西洋冷团的贡献是相等的。这些结果突出了AMOC对大气特性及其辐射效应的影响的重要性。
附：英文原文
Title: Subpolar North Atlantic cooling reinforced by colder, drier atmosphere with a weakening Atlantic meridional overturning circulation
Author: Yifei Fan, Duo Chan, Eugene E. Clothiaux, Pengfei Zhang, Laifang Li
Issue&Volume: 2025-06-06
Abstract: In contrast to global warming, the subpolar North Atlantic has experienced long-term cooling throughout the 20th century. This cooling, known as the North Atlantic cold blob, has been hypothesized to arise from reduced poleward oceanic heat transport associated with a slowdown of the Atlantic meridional overturning circulation (AMOC). Here, by diagnosing historical simulations from multiple coupled climate models, we find that ocean heat transport is not the only pathway through which the AMOC modulates sea surface temperature variability. A weakened AMOC is also associated with colder, drier lower atmospheric conditions, which lead to a reduction in surface warming expected from increasing amounts of heat-trapping gases by reducing downward clear-sky longwave radiation at the surface. This radiative pathway and the oceanic processes contribute equally to the North Atlantic cold blob. These results highlight the importance of the AMOC’s impact on atmospheric properties and their radiative effects.
DOI: ads1624
Source: https://www.science.org/doi/10.1126/sciadv.ads1624