Understanding the combined effect of El Nino-Southern Oscillation (ENSO) and the North Atlantic Oscillation (NAO) is of great importance for climate seasonal prediction (extreme climate events in particular). Results in this study show that during thelast hundred years (1900 to present), the ENSO-NAO connection experiences a notable interdecadal change in summer (June-August) according to a 21-year sliding correlation between them, namely, from no significant correlation (uncoupling) before the mid-1970s to a significant correlation (coupling) after the mid-1970s. Comparison analysis between the coupling epoch (1977-1997) and the uncoupling epoch (1958-1976) shows that the most pronounced circulation anomalies take place over the extratropical North Pacific. Further analysis and numerical experiments suggest that a poleward-propagating Rossby wave train, possibly enhanced by sea-surface-temperature anomalies in the extratropical North Pacific associated with the developing phases of ENSO during the later epoch, is responsible for connecting the ENSO signal with the NAO.
展开▼
机译：了解厄尔尼诺-南方涛动（ENSO）和北大西洋涛动（NAO）的综合影响对于气候季节预测（尤其是极端气候事件）具有重要意义。这项研究的结果表明，在最近的一百年（1900年至今）中，ENSO-NAO连接根据它们之间的21年滑动相关性经历了夏季（6月至8月）的年代际变化，即从无显着相关性开始。 1970年代中期之前的（耦合）与1970年代中期之后的显着相关（耦合）。耦合时期（1977-1997）和非耦合时期（1958-1976）之间的比较分析表明，最明显的环流异常发生在温带北太平洋上空。进一步的分析和数值实验表明，极地传播的罗斯比波列可能是由于与晚些时候ENSO的发展阶段有关的温带北太平洋海温异常而增强的，它负责将ENSO信号与海平面相连接。 AO
展开▼
