Environnements et Paléoenvironnements Océaniques et Continentaux (EPOC), UMR CNRS 5805 EPOC-OASU-Université de Bordeaux, Allée Geoffroy Saint-Hilaire, Pessac 33615, France.
LOCEAN/IPSL Sorbonne Universités (UPMC, Univ Paris 06)-CNRS-IRD-MNHN, 4 place Jussieu, Paris F-75005, France.
Nat Commun. 2015 Mar 30;6:6545. doi: 10.1038/ncomms7545.
While bidecadal climate variability has been evidenced in several North Atlantic paleoclimate records, its drivers remain poorly understood. Here we show that the subset of CMIP5 historical climate simulations that produce such bidecadal variability exhibits a robust synchronization, with a maximum in Atlantic Meridional Overturning Circulation (AMOC) 15 years after the 1963 Agung eruption. The mechanisms at play involve salinity advection from the Arctic and explain the timing of Great Salinity Anomalies observed in the 1970s and the 1990s. Simulations, as well as Greenland and Iceland paleoclimate records, indicate that coherent bidecadal cycles were excited following five Agung-like volcanic eruptions of the last millennium. Climate simulations and a conceptual model reveal that destructive interference caused by the Pinatubo 1991 eruption may have damped the observed decreasing trend of the AMOC in the 2000s. Our results imply a long-lasting climatic impact and predictability following the next Agung-like eruption.
虽然北大西洋古气候记录中已经出现了双十年际气候变率，但其驱动因素仍不清楚。在这里，我们表明，在产生这种双十年际变化的 CMIP5 历史气候模拟中，大西洋经向翻转环流（AMOC）在 1963 年阿贡火山爆发 15 年后表现出很强的同步性。起作用的机制涉及来自北极的盐度平流，并解释了 20 世纪 70 年代和 90 年代观测到的大盐度异常的时间。模拟以及格陵兰和冰岛古气候记录表明，在上一个千年的五次类似于阿贡火山的喷发之后，双十年际的连贯周期被激发。气候模拟和一个概念模型表明，1991 年皮纳图博火山喷发造成的破坏性干扰可能削弱了本世纪 2000 年代观测到的 AMOC 下降趋势。我们的结果表明，在下一次类似于阿贡火山的喷发之后，将产生持久的气候影响和可预测性。
