Remote influence of Atlantic multidecadal variability on Siberian warm season precipitation.
Remote influence of Atlantic multidecadal variability on Siberian warm season precipitation.
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大西洋数十年变率对西伯利亚暖季降水的远程影响
DOI：
10.1038/srep16853
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发表时间：
2015-11-23
影响因子：
4.6
通讯作者：
Zhao S
中科院分区：
文献类型：
--
作者：
Sun C;Li J;Zhao S
20世纪西伯利亚暖季（5月至10月）降水（SWP）的时间序列在十年尺度上呈现出变化，包括自20世纪70年代以来的湿润趋势。在此表明，大西洋多年代际变率（AMV）可被视为西伯利亚暖季降水十年尺度变化的一个遥相关驱动因子。观测分析确定了大西洋多年代际变率与西伯利亚暖季降水之间存在显著的同位相关系，并且西伯利亚暖季降水的十年变率在很大程度上可由大西洋多年代际变率来解释。利用观测和数值模拟对这种关系的物理机制进行了研究。结果表明，与大西洋多年代际变率正位相相关的北大西洋海表温度（SST）变暖能够激发一个横跨整个欧亚大陆向东传播的波列响应，其中在西伯利亚上空包含一个东西向的偶极子结构。该偶极子随后导致异常的南风将水汽向北输送到西伯利亚；降水相应增加。线性正压模式和罗斯贝波射线追踪分析进一步支持了这一机制。
The time series of 20th century Siberian warm season (May to October) precipitation (SWP) shows variations over decadal timescales, including a wetting trend since the 1970s. Here, it is shown that the Atlantic multidecadal variability (AMV) can be implicated as a remote driver of the decadal-scale variations in SWP. Observational analysis identifies a significant in-phase relationship between the AMV and SWP and the SWP decadal variability can be largely explained by the AMV. The physical mechanism for this relationship is investigated using both observations and numerical simulations. The results suggest that North Atlantic sea surface temperature (SST) warming associated with the positive AMV phase can excite an eastward propagating wave train response across the entire Eurasian continent, which includes an east–west dipole structure over Siberia. The dipole then leads to anomalous southerly winds bringing moisture northward to Siberia; the precipitation increases correspondingly. The mechanism is further supported by linear barotropic modeling and Rossby wave ray tracing analysis.