The Program in Atmospheric and Oceanic Sciences, Princeton University, Princeton, NJ, 08540, USA.
NOAA/GFDL, Princeton, NJ, 08540, USA.
Nat Commun. 2017 Nov 22;8(1):1695. doi: 10.1038/s41467-017-01377-8.
Observed Atlantic major hurricane frequency has exhibited pronounced multidecadal variability since the 1940s. However, the cause of this variability is debated. Using observations and a coupled earth system model (GFDL-ESM2G), here we show that the decline of the Atlantic major hurricane frequency during 2005-2015 is associated with a weakening of the Atlantic Meridional Overturning Circulation (AMOC) inferred from ocean observations. Directly observed North Atlantic sulfate aerosol optical depth has not increased (but shows a modest decline) over this period, suggesting the decline of the Atlantic major hurricane frequency during 2005-2015 is not likely due to recent changes in anthropogenic sulfate aerosols. Instead, we find coherent multidecadal variations involving the inferred AMOC and Atlantic major hurricane frequency, along with indices of Atlantic Multidecadal Variability and inverted vertical wind shear. Our results provide evidence for an important role of the AMOC in the recent decline of Atlantic major hurricane frequency.
自 20 世纪 40 年代以来，观测到的北大西洋大型飓风频率呈现出明显的多年代际变化。然而，这种变化的原因仍存在争议。本研究利用观测资料和一个耦合地球系统模式（GFDL-ESM2G），结果表明，2005-2015 年北大西洋大型飓风频率的下降与海洋观测推断的大西洋经向翻转环流（AMOC）减弱有关。在此期间，直接观测到的北大西洋硫酸盐气溶胶光学厚度并没有增加（但略有下降），这表明 2005-2015 年北大西洋大型飓风频率的下降不太可能是由于人为硫酸盐气溶胶的近期变化造成的。相反，我们发现涉及推断的 AMOC 和北大西洋大型飓风频率的一致的多年代际变化，以及大西洋多年代际变率和垂直风切变的反转指数。我们的研究结果为 AMOC 在最近北大西洋大型飓风频率下降中的重要作用提供了证据。
