We demonstrate a 1-year lagged extratropical response to the El Niño–Southern Oscillation (ENSO) in observational analyses and climate models. The response maps onto the Arctic Oscillation and is strongest in the North Atlantic, where it resembles the North Atlantic Oscillation (NAO). Unexpectedly, these 1-year lagged teleconnections are at least as strong as the better-known simultaneous winter connections. However, the 1-year lagged response is opposite in sign to the simultaneous response such that 1 year later, El Niño is followed by a positive NAO, whereas La Niña is followed by a negative NAO. The lagged response may also interfere with simultaneous ENSO teleconnections. We show here that these effects are unlikely to be caused by residual aliasing of ENSO cycles; rather, slowly migrating atmospheric angular momentum anomalies explain both the sign and the timing of the extratropical response. Our results have implications for understanding ENSO teleconnections, explaining observed extratropical climate variability and interpreting seasonal to interannual climate predictions.

中文翻译：

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ENSO 影响 1 年后的北大西洋涛动


我们在观测分析和气候模型中证明了对厄尔尼诺-南方涛动 （ENSO） 的 1 年滞后温带响应。该响应映射到北极涛动，在北大西洋最强，类似于北大西洋涛动 （NAO）。出乎意料的是，这些 1 年滞后的遥相关至少与更知名的冬季同步连接一样强大。然而，1 年滞后反应与同时反应的符号相反，因此 1 年后，厄尔尼诺现象之后是阳性 NAO，而拉尼娜现象之后是阴性 NAO。滞后响应也可能干扰同步 ENSO 远程连接。我们在这里表明，这些影响不太可能是由 ENSO 循环的残余混叠引起的;相反，缓慢迁移的大气角动量异常解释了温带响应的迹象和时间。我们的结果对理解 ENSO 遥相关、解释观察到的温带气候变化以及解释季节性到年际气候预测具有意义。