Abstract We show evidence that tropical atmospheric variability over the central tropical Pacific modulates the circulation over the western Arctic and the North Atlantic-European sector, impacting the summer precipitation especially over Nordic European countries (NEC). Our results, based on the ERA5 reanalysis, suggest the occurrence of a teleconnection mechanism (similar to the Pacific North American pattern) between the tropical Pacific in early spring and summer precipitation over NEC, and we propose two indices as predictors for NEC summer precipitation based on geopotential height anomalies at 500 hPa over the western tropical Pacific during March. We propose an empirical model based on both indices as predictors and assess the model’s skill with a leave-one-out cross-validation procedure. Over large portions of NEC, our proposed empirical model is able to reproduce dry, normal and wet years, defined from summer standardized precipitation anomalies, with a Heidke skill score greater than 0.9.

中文翻译：

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确定与全球遥相关波模式相关的北欧国家夏季降水年际变率的远程来源

摘要 我们证明，热带太平洋中部的热带大气变率调节了北极西部和北大西洋-欧洲部分的环流，影响了夏季降水，尤其是北欧国家 (NEC)。我们基于 ERA5 再分析的结果表明，NEC 早春和夏季降水在热带太平洋之间存在遥相关机制（类似于北美太平洋模式），我们提出了两个指数作为 NEC 夏季降水的预测因子。 3 月西热带太平洋上空 500 hPa 的位势高度异常。我们提出了一个基于两个指数作为预测变量的经验模型，并通过留一法交叉验证程序评估模型的技能。在 NEC 的大部分地区，