The water cycle over middle‐ to high‐latitude regions has experienced rapid changes in recent decades. The sea surface temperature (SST) and Arctic sea ice influence the water cycle over these regions, but the relative roles of SST warming and the loss of Arctic sea ice remain unclear. We identify an enhanced change in the summer (June–August) water cycle over northeastern Siberia (55–70°N, 100–170°E) during the last three decades. The driving force of this enhanced wetting trend is investigated using both observations and model simulations. An increasing trend of low‐level southerly winds and a decrease in sea‐level pressure are observed over northeastern Siberia during summer, leading to stronger lower tropospheric moisture convergence and ascending motion, which favor an increase in precipitation. The wetting trend and the associated atmospheric features are successfully reproduced by an atmospheric model driven by the observed Arctic sea ice concentrations and SSTs, whereas the model driven solely by the Arctic sea ice concentrations simulates a negligible increase in precipitation. This is primarily due to the absence of the stronger southerly winds that transport moisture from the Pacific Ocean. The modeling evidence suggests that SST changes in recent decades have a stronger influence on the intensified precipitation than does sea ice. An atmospheric bridge mechanism links the strengthened southerly winds to an upper‐level Rossby wave train originating from the North Atlantic. Another atmospheric simulation forced only by Atlantic SST warming recreates the observed enhanced wetting trend in northeastern Siberia and supports the hypothesized atmospheric bridge mechanism.

中文翻译：

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近几十年来海温升高和北极海冰流失在东北西伯利亚夏季湿润趋势增强中的作用

近几十年来，中高纬度地区的水循环经历了快速变化。海表温度（SST）和北极海冰影响了这些地区的水循环，但尚不清楚SST变暖和北极海冰损失的相对作用。我们发现在过去的三十年中，西伯利亚东北部（55-70°N，100-170°E）夏季（6月至8月）水循环变化增强。使用观察和模型仿真研究了这种增强的润湿趋势的驱动力。夏季期间，西伯利亚东北部观测到低水平的南风增加趋势和海平面压力降低，导致对流层较低的水汽汇聚和上升运动，这有利于降水增加。观测到的北极海冰浓度和SST驱动的大气模型成功地再现了润湿趋势和相关的大气特征，而仅由北极海冰浓度驱动的模型模拟的降水量可忽略不计。这主要是由于缺少从太平洋输送水分的较强的南风。模拟证据表明，近几十年来海表温度的变化比海冰对强化降水的影响更大。大气桥机制将增强的南风连接到源自北大西洋的高层罗斯比波列。