Institute for Marine and Atmospheric research Utrecht (IMAU), Department of Physics, Utrecht University, Utrecht, the Netherlands.
Environnements et Paléoenvironnements Océaniques et Continentaux (EPOC), Université de Bordeaux, Allée Geoffroy Saint-Hilaire, Pessac, 33615, France.
Nat Commun. 2022 Sep 2;13(1):5176. doi: 10.1038/s41467-022-32704-3.
Atlantic multidecadal variability is a coherent mode of natural climate variability occurring in the North Atlantic Ocean, with strong impacts on human societies and ecosystems worldwide. However, its periodicity and drivers are widely debated due to the short temporal extent of instrumental observations and competing effects of both internal and external climate factors acting on North Atlantic surface temperature variability. Here, we use a paleoclimate database and an advanced statistical framework to generate, evaluate, and compare 312 reconstructions of the Atlantic multidecadal variability over the past millennium, based on different indices and regression methods. From this process, the best reconstruction is obtained with the random forest method, and its robustness is checked using climate model outputs and independent oceanic paleoclimate data. This reconstruction shows that memory in variations of Atlantic multidecadal variability have strongly increased recently-a potential early warning signal for the approach of a North Atlantic tipping point.
北大西洋多年代际变率是一种发生在北大西洋的自然气候变化的连贯模式，对全球人类社会和生态系统有着强烈的影响。然而，由于仪器观测的时间范围较短，以及影响北大西洋表面温度变化的内部和外部气候因素的竞争效应，其周期性和驱动因素仍存在广泛争议。在这里，我们使用古气候数据库和先进的统计框架，基于不同的指标和回归方法，生成、评估和比较了过去一千年中北大西洋多年代际变率的 312 个重建结果。在此过程中，我们使用随机森林方法获得了最佳重建结果，并使用气候模型输出和独立的海洋古气候数据来检查其稳健性。该重建结果表明，大西洋多年代际变率变化的记忆近期以来急剧增强——这可能是北大西洋 tipping point 即将到来的一个早期预警信号。
