We investigate the climate signature of δ¹⁸O tree-ring records from sites distributed all over Europe covering the last 400 years. An empirical orthogonal function (EOF) analysis reveals two distinct modes of variability on the basis of the existing δ¹⁸O tree-ring records. The first mode is associated with anomaly patterns projecting onto the El Niño–Southern Oscillation (ENSO) and reflects a multi-seasonal climatic signal. The ENSO link is pronounced for the last 130 years, but it is found to be weak over the period from 1600 to 1850, suggesting that the relationship between ENSO and the European climate may not be stable over time. The second mode of δ¹⁸O variability, which captures a north–south dipole in the European δ¹⁸O tree-ring records, is related to a regional summer atmospheric circulation pattern, revealing a pronounced centre over the North Sea. Locally, the δ¹⁸O anomalies associated with this mode show the same (opposite) sign with temperature (precipitation). Based on the oxygen isotopic signature derived from tree rings, we argue that the prevailing large-scale atmospheric circulation patterns and the related teleconnections can be analysed beyond instrumental records.

中文翻译：

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来自树木年轮的欧洲氧同位素网络的大规模气候信号

我们调查的气候签名δ ¹⁸ Ø从站点遍布欧洲树木年轮记录涵盖了过去的400年。一个经验正交函数（EOF）分析揭示的现有的基础上变化的两种不同的模式δ ¹⁸ ö树轮记录。第一种模式与投射到厄尔尼诺-南方涛动（ENSO）上的异常模式有关，并反映了一个多季节的气候信号。ENSO链接在过去的130年中一直很明显，但是在1600年到1850年之间发现它很弱，这表明ENSO和欧洲气候之间的关系可能会随着时间的推移而变得不稳定。的第二模式δ ¹⁸ ö变化，捕捉在欧洲南北偶极δ ¹⁸ Ø树木年轮记录，关系到一个地区的夏季大气环流模式，揭示了北海明显的中心。在本地，δ ¹⁸ ö与此模式有关的异常显示出与温度（沉淀）相同的（相对的）符号。基于从树木年轮获得的氧同位素特征，我们认为，除了仪器记录外，可以分析盛行的大规模大气环流模式和相关的遥相关。