Yamamoto Ayako, Palter Jaime B
Department of Atmospheric and Oceanic Sciences, McGill University, 805 Sherbrooke Street West, Montreal, Quebec, Canada H3A 2K6.
Graduate School of Oceanography, University of Rhode Island, Narragansett Bay Campus, Narragansett, Rhode Island 02882, USA.
Nat Commun. 2016 Mar 15;7:10930. doi: 10.1038/ncomms10930.
Northern Hemisphere climate responds sensitively to multidecadal variability in North Atlantic sea surface temperature (SST). It is therefore surprising that an imprint of such variability is conspicuously absent in wintertime western European temperature, despite that Europe's climate is strongly influenced by its neighbouring ocean, where multidecadal variability in basin-average SST persists in all seasons. Here we trace the cause of this missing imprint to a dynamic anomaly of the atmospheric circulation that masks its thermodynamic response to SST anomalies. Specifically, differences in the pathways Lagrangian particles take to Europe during anomalous SST winters suppress the expected fluctuations in air-sea heat exchange accumulated along those trajectories. Because decadal variability in North Atlantic-average SST may be driven partly by the Atlantic Meridional Overturning Circulation (AMOC), the atmosphere's dynamical adjustment to this mode of variability may have important implications for the European wintertime temperature response to a projected twenty-first century AMOC decline.
北半球气候对北大西洋海表温度（SST）的多年代际变化反应敏感。因此，令人惊讶的是，尽管欧洲气候受到其邻近海洋的强烈影响，且该海域的海盆平均海表温度在所有季节都存在多年代际变化，但这种变化在西欧冬季温度中却明显没有留下印记。在这里，我们将这种缺失印记的原因追溯到大气环流的一个动态异常，它掩盖了大气对海表温度异常的热力响应。具体而言，在海表温度异常的冬季，拉格朗日粒子到达欧洲的路径差异抑制了沿这些轨迹积累的海气热交换的预期波动。由于北大西洋平均海表温度的年代际变化可能部分由大西洋经向翻转环流（AMOC）驱动，大气对这种变化模式的动态调整可能对欧洲冬季温度对预计的21世纪AMOC下降的响应具有重要影响。
