Observation-based early-warning signals for a collapse of the Atlantic Meridional Overturning Circulation
Observation-based early-warning signals for a collapse of the Atlantic Meridional Overturning Circulation
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DOI：
10.1038/s41558-021-01097-4
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发表时间：
2021-08-01
影响因子：
30.7
通讯作者：
Boers, Niklas
中科院分区：
文献类型：
--
作者：
Boers, Niklas
大西洋子午线翻转环流(AMOC)是一个主要的洋流系统，将表层温暖的海水输送到北大西洋，已经被认为表现出两种不同的运行模式。从目前获得的强模式到弱模式的崩溃将对全球气候系统和进一步的多稳定地球系统组成部分产生严重影响。观察结果和最近提出的AMOC变异性的指纹表明，在过去的几十年里，AMOC的变异性逐渐减弱，但对关键转换点的估计仍然不确定。在这里，介绍了对即将到来的关键过渡的强有力和一般性的预警指标。根据整个大西洋盆地的观测海面温度和盐度数据，在8个独立的AMOC指数中发现了重要的预警信号。这些结果揭示了空间上一致的经验证据，表明在上个世纪的过程中，AMOC可能从相对稳定的条件演变到接近临界点的转折点。大西洋子午线翻转环流(AMOC)目前很强，但转换到它的弱模可能会导致气候系统的重大变化。这项工作为这种过渡提供了一个基于观测的早期预警系统，并表明AMOC可能正在接近过渡。
The Atlantic Meridional Overturning Circulation (AMOC), a major ocean current system transporting warm surface waters toward the northern Atlantic, has been suggested to exhibit two distinct modes of operation. A collapse from the currently attained strong to the weak mode would have severe impacts on the global climate system and further multi-stable Earth system components. Observations and recently suggested fingerprints of AMOC variability indicate a gradual weakening during the last decades, but estimates of the critical transition point remain uncertain. Here, a robust and general early-warning indicator for forthcoming critical transitions is introduced. Significant early-warning signals are found in eight independent AMOC indices, based on observational sea-surface temperature and salinity data from across the Atlantic Ocean basin. These results reveal spatially consistent empirical evidence that, in the course of the last century, the AMOC may have evolved from relatively stable conditions to a point close to a critical transition.The Atlantic Meridional Overturning Circulation (AMOC) is currently strong, but transition to its weak mode could see significant changes in the climate system. This work presents an observation-based early-warning system for such transitions and shows that the AMOC may be approaching a transition.