Department of Physics, University of Toronto, Toronto, Ontario Canada.
Department of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, Ontario, Canada.
Sci Rep. 2017 Jan 23;7:40861. doi: 10.1038/srep40861.
North Atlantic sea surface temperatures experience variability with a periodicity of 60-80 years that is known as the Atlantic Multidecadal Oscillation (AMO). It has a profound imprint on the global climate system that results in a number of high value societal impacts. However the industrial period, i.e. the middle of the 19th century onwards, contains only two full cycles of the AMO making it difficult to fully characterize this oscillation and its impact on the climate system. As a result, there is a clear need to identify paleoclimate records extending into the pre-industrial period that contain an expression of the AMO. This is especially true for extratropical marine paleoclimate proxies where such expressions are currently unavailable. Here we present an annually resolved coralline algal time series from the northwest Atlantic Ocean that exhibits multidecadal variability extending back six centuries. The time series contains a statistically significant trend towards higher values, i.e. warmer conditions, beginning in the 19th century that coincided with an increase in the time series' multidecadal power. We argue that these changes are associated with a regional climate reorganization involving an amplification of the AMO that coincided with onset of the industrial-era warming.
北大西洋海表温度具有 60-80 年的周期性变化，被称为北大西洋多年代际振荡（AMO）。它对全球气候系统有深远的影响，导致了许多高价值的社会影响。然而，工业时期（即 19 世纪中叶以来）只包含了 AMO 的两个完整周期，这使得很难完全描述这种振荡及其对气候系统的影响。因此，显然需要确定包含 AMO 表达的延伸到前工业化时期的古气候记录。对于目前尚无此类表达的亚热带海洋古气候代理尤其如此。在这里，我们展示了来自北大西洋西北部的一个年度分辨率的珊瑚藻时间序列，该序列显示了可追溯到六百年前的多十年变化。该时间序列包含一个在 19 世纪开始的、呈上升趋势的统计显著的数值，即更温暖的条件，这与时间序列的多十年功率增加相吻合。我们认为这些变化与区域气候重组有关，其中包括 AMO 的放大，这与工业时代变暖的开始相吻合。
