We find a positive phase of meridional tripole pattern of boreal autumn sea surface temperature anomalies over the tropical and South Pacific (TSPT+ ) has a synergistic effect with winter negative NAO (NAO−) on the amplitude and occurrence of winter precipitation in southern Europe (SEWP). This synergistic effect is attributed to the linear superposition and nonlinear effect of winter NAO− and preceding autumn TSPT+ . The autumn TSPT+ can persist into winter, and the winter TSPT+ with NAO− can stimulate a greater amount of Rossby wave energy propagating to the North Atlantic-Europe (NAE) region than without NAO−, and thereby synergistically regulating circulation with winter NAO−. Thus, winter NAO− and autumn TSPT+ have a synergistic effect on the northwest-southeast trending positive-negative-positive winter circulation over the NAE region. Driven by the intensified mean circulation, water vapor transports and storm activity over southern Europe are evidently strong, which is in favor of SEWP formation.

我们发现热带和南太平洋北部秋季海表温度异常的经向三极格局的正相位（TSPT+）与冬季负NAO（NAO−）对南欧冬季降水的幅度和发生具有协同效应（SEWP） ）。这种协同效应归因于冬季NAO−和前期秋季TSPT+的线性叠加和非线性效应。秋季TSPT+可以持续到冬季，并且与没有NAO−的冬季TSPT+相比，有NAO−的冬季TSPT+可以激发更多的罗斯贝波能量传播到北大西洋-欧洲（NAE）地区，从而与冬季NAO−协同调节环流。因此，冬季NAO−和秋季TSPT+对NAE地区冬季西北-东南趋势的正-负-正冬季环流具有协同作用。在平均环流增强的推动下，南欧地区水汽输送和风暴活动明显较强，有利于SEWP的形成。