Determining whether the Atlantic Meridional Overturning Circulation (AMOC)'s transport is in decline is challenging due to the short duration of continuous observations. To estimate how many years are needed to detect a decline, we conduct a simulation study using synthetic data that mimics an AMOC time series. The time series' characteristics are reproduced using the trend, variance, and autocorrelation coefficient of the AMOC strength at 26.5°N from 20 Coupled Model Intercomparison Project Phase 5 (CMIP5) models under the RCP8.5 future scenario, and from RAPID observations (2004–2018). Our results suggest that the 14‐year RAPID length has just entered the lower limits of the trend's “detection window” based on synthetic data generated using CMIP5 trends and variability (14–42 years; median urn:x-wiley:grl:media:grl61393:grl61393-math-0001 24 years), but twice the length is required for detectability based on RAPID variability (29–67 years; median urn:x-wiley:grl:media:grl61393:grl61393-math-0002 43 years). The annual RAPID trend is currently not statistically significant (−0.11 Sv yr−1, p > 0.05).

中文翻译：

---

当前和预计的气候变化中 AMOC 下降的可检测性

由于连续观测的持续时间较短，确定大西洋经向翻转环流 (AMOC) 的传输是否在下降具有挑战性。为了估计检测下降需要多少年，我们使用模拟 AMOC 时间序列的合成数据进行模拟研究。时间序列的特征是使用 RCP8.5 未来情景下 20 个耦合模型比对项目第 5 阶段 (CMIP5) 模型和 RAPID 观测（2004 年）在 26.5°N 处的 AMOC 强度的趋势、方差和自相关系数再现的–2018）。我们的结果表明，基于使用 CMIP5 趋势和可变性（14-42 年；中位数 urn:x-wiley:grl:media: 生成的合成数据），14 年 RAPID 长度刚刚进入趋势“检测窗口”的下限： grl61393：grl61393-math-0001 24 年），但基于 RAPID 变异性（29-67 年；中位数 urn:x-wiley:grl:media:grl61393:grl61393-math-0002 43 年）的可检测性需要两倍的长度。年度 RAPID 趋势目前在统计上不显着（-0.11 Sv yr-1，p > 0.05）。