University Ca'Foscari of Venice, Dept. of Environmental Sciences, Informatics and Statistics, Via Torino 155, 30172, Mestre Venezia, Italy.
NORCE Norwegian Research Centre, Bjerknes Centre for Climate Research, Jahnebakken 5, 5007, Bergen, Norway.
Sci Rep. 2019 Jul 29;9(1):10998. doi: 10.1038/s41598-019-47428-6.
Discharge time series of major large-catchment European rivers are known to display significant decadal and interdecadal fluctuations. However, the hydroclimate variability causing such fluctuations remains poorly understood, particularly due to a lack of a spatio-temporal integrated assessment. Here, we demonstrate for the first time that European hydroclimate variability is dominated by a meridional delayed oscillation characterized by a lag of approximately 5 years in interdecadal discharge fluctuations of continental (northern) European rivers with respect to those of Euro-Mediterranean (southern) rivers. We demonstrate a connection of this coherent signal with the large-scale atmospheric circulation over the North Atlantic, and suggest a hitherto unexplored multiannual atmosphere-ocean mechanism in the subpolar North Atlantic at its root.
主要的欧洲大流域的排放时间序列已知显示出显著的十年际和数十年际波动。然而，导致这种波动的水文气候可变性仍然知之甚少，特别是由于缺乏时空综合评估。在这里，我们首次证明，欧洲水文气候的可变性主要由纬向延迟振荡所主导，其特征是欧洲大陆（北部）河流的年代际排放波动相对于欧洲-地中海（南部）河流的波动存在约 5 年的滞后。我们证明了这种相干信号与北大西洋的大尺度大气环流有关，并提出了一个迄今为止尚未探索的在北大西洋亚极地的多年份大气-海洋机制。
