Spring freshet is the dominant annual discharge event in all major Arctic draining rivers with large contributions to freshwater inflow to the Arctic Ocean. Research has shown that the total freshwater influx to the Arctic Ocean has been increasing, while at the same time, the rate of change in the Arctic climate is significantly higher than in other parts of the globe. This study assesses the large-scale atmospheric and surface climatic conditions affecting the magnitude, timing and regional variability of the spring freshets by analyzing historic daily discharges from sub-basins within the four largest Arctic-draining watersheds (Mackenzie, Ob, Lena and Yenisei). Results reveal that climatic variations closely match the observed regional trends of increasing cold-season flows and earlier freshets. Flow regulation appears to suppress the effects of climatic drivers on freshet volume but does not have a significant impact on peak freshet magnitude or timing measures. Spring freshet characteristics are also influenced by El Niño-Southern Oscillation, the Pacific Decadal Oscillation, the Arctic Oscillation and the North Atlantic Oscillation, particularly in their positive phases. The majority of significant relationships are found in unregulated stations. This study provides a key insight into the climatic drivers of observed trends in freshet characteristics, whilst clarifying the effects of regulation versus climate at the sub-basin scale.

中文翻译：

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气候驱动因素和遥相关因素对四大北极流域河流春季新生的20世纪后期趋势的影响

在所有主要的北极排水河流中，春季新生水是主要的年度排放事件，对淡水流入北冰洋的贡献很大。研究表明，流入北冰洋的淡水总量一直在增加，而与此同时，北冰洋气候的变化速度明显高于全球其他地区。这项研究通过分析四个最大的北极排水流域（Mackenzie，Ob，Lena和Yenisei）次流域的历史日排放量，评估了影响春季新生的规模，时间和区域变异性的大规模大气和地表气候条件。结果表明，气候变化与寒冷季节流量增加和较早新生所观测到的区域趋势非常吻合。流量调节似乎可以抑制气候驱动因素对生鲜量的影响，但对生鲜峰值量或时间措施没有显着影响。春季新生的特征还受到厄尔尼诺-南方涛动，太平洋年代际涛动，北极涛动和北大西洋涛动的影响，尤其是在积极时期。大多数重要关系都存在于不受管制的站点中。这项研究提供了对观测到的新生特征趋势的气候驱动因素的关键见解，同时阐明了在流域范围内调节与气候的影响。太平洋年代际涛动，北极涛动和北大西洋涛动，特别是在积极时期。大多数重要关系都存在于不受管制的站点中。这项研究提供了对观测到的新生特征趋势的气候驱动因素的关键见解，同时阐明了在流域范围内调节与气候的影响。太平洋年代际涛动，北极涛动和北大西洋涛动，特别是在积极时期。大多数重要关系都存在于不受管制的站点中。这项研究提供了对观测到的新生特征趋势的气候驱动因素的关键见解，同时阐明了在流域范围内调节与气候的影响。