Fluctuations in the relationship between the Silk Road Pattern and the summer North Atlantic Oscillation

This study investigated the fluctuations in the relationship between the Silk Road Pattern (SRP) and the boreal summer North Atlantic Oscillation (SNAO). The results indicated that the SRP–SNAO relationship was relatively weak during 1958–2022, which was primarily due to fluctuations, particularly the reversal in their relationship since the late 1990s. Using wavelet coherence analysis, the authors identified a strong SRP–SNAO linkage on a 4–8-yr timescale, in particular during the mid-1970s to the early/mid-1990s. This strong linkage is mainly attributable to the intensification and eastward movement of the southern part of the SNAO around the mid/late 1970s, which favored the strong connection between the SNAO and the SRP. Additionally, the interdecadal changes of the atmospheric circulations over the North Atlantic and Eurasia around the mid/late 1970s that resembled the circulation anomalies related to the strong SRP–SNAO linkage, may also have provided a favorable background for the strong connection between the two teleconnections. These findings on the fluctuations in the SRP–SNAO linkage may offer important implications for understanding the impact of the SNAO on the SRP and the variability of the SRP.

摘要

本文利用近60年大气再分析数据, 研究了丝绸之路型遥相关 (Silk Road Pattern, SRP) 与夏季北大西洋涛动 (North Atlantic Oscillation, SNAO) 关系的不稳定性及其可能成因. 结果表明, 近60年来, SRP与SNAO的关系具有明显的不稳定性. 两者关系在1970s中期至1990s中期显著增强, 特别在4-8年时间尺度上. 两者关系的增强主要与1970s中后期以来SNAO南部中心增强, 位置东移有关. 同时, 北大西洋和欧亚区域夏季大气环流在1970s末的年代际异常也为两者之间关系的增强提供了有利的气候背景.