大西洋经向翻转环流（AMOC）是全球气候的一个关键组成部分，预计在未来人为气候变化的影响下，该环流将减弱。虽然许多研究调查了AMOC对气候模式中不同水平和类型强迫的响应，但相对较少关注AMOC对强迫变化率的敏感性，尽管它在未来排放情景中也具有高度的不确定性。
在这项研究中，作者在一个先进的全球气候模型中，分离出AMOC对不同CO2增长速度的响应，发现即使在CO2变化幅度相同的情况下，AMOC在更快的CO2变化速度下也会经历更严重的减弱。
然后，作者提出了一个AMOC-海洋热输送-海冰反馈，它增强了环流的下降，并解释了对强迫变化速率的依赖。AMOC对速率敏感的行为，导致在相同的CO2浓度下产生不同的气候（包括不同的北极海冰演变），这突出了强迫变化的速率本身，是全球气候变化的关键驱动因素。
附：英文原文
Title: The effect of CO2 ramping rate on the transient weakening of the Atlantic Meridional Overturning Circulation
Author: Hankel, Camille
Issue&Volume: 2024-12-23
Abstract: The Atlantic Meridional Overturning Circulation (AMOC) is a key component of the global climate that is projected to weaken under future anthropogenic climate change. While many studies have investigated the AMOC’s response to different levels and types of forcing in climate models, relatively little attention has been paid to the AMOC’s sensitivity to the rate of forcing change, despite it also being highly uncertain in future emissions scenarios. In this study, I isolate the AMOC’s response to different rates of CO2 increase in a state-of-the-art global climate model and find that the AMOC undergoes more severe weakening under faster rates of CO2 change, even when the magnitude of CO2 change is the same. I then propose an AMOC-ocean heat transport-sea ice feedback that enhances the decline of the circulation and explains the dependence on the rate of forcing change. The AMOC’s rate-sensitive behavior leads to qualitatively different climates (including differing Arctic sea ice evolution) at the same CO2 concentration, highlighting how the rate of forcing change is itself a key driver of global climatic change.
DOI: 10.1073/pnas.2411357121
Source: https://www.pnas.org/doi/abs/10.1073/pnas.2411357121