Major sudden stratospheric warmings (SSWs) are the most important phenomena of the wintertime boreal stratospheric variability. During SSWs, the polar temperature increases abruptly, and easterlies prevail in the stratosphere. Their effects extend farther from the polar stratosphere, affecting near-surface circulation. According to observations, SSWs are not equally distributed in time, with decades experiencing very few events, while others experiencing SSWs almost every winter. Some sources of this SSW multidecadal variability can be traced back to sea surface temperature changes. Here, we investigate the effects of Pacific decadal variability (PDV) and Atlantic multidecadal variability (AMV) on SSWs. We use for the first time a large ensemble of historical experiments to examine the modulation of the frequency, tropospheric precursors, and impact of SSWs by the PDV and AMV. We find a strong impact of the PDV on the occurrence of SSWs, with a higher SSW frequency for the positive phase of the PDV. This PDV influence is mediated by constructive interference of PDV anomalies with tropospheric stationary waves. The main effect of AMV is, instead, a modulation of the tropospheric response to SSWs, a finding that can be useful for predicting the tropospheric fingerprint of SSWs.

中文翻译：

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十年间至多年间海洋变率与平流层突然变暖之间的相互作用

主要的突然平流层变暖（SSWs）是冬季北方平流层变率的最重要现象。在 SSW 期间，极地温度突然升高，平流层盛行东风。它们的影响从极地平流层延伸得更远，影响近地表环流。根据观察，SSW 在时间上分布不均，几十年发生的事件很少，而其他人几乎每年冬天都会经历 SSW。这种 SSW 年代际变化的一些来源可以追溯到海面温度变化。在这里，我们调查了太平洋年代际变率 (PDV) 和大西洋年代际变率 (AMV) 对 SSW 的影响。我们首次使用大量历史实验来检查频率的调制、对流层前兆、PDV 和 AMV 对 SSW 的影响。我们发现 PDV 对 SSW 的发生有很强的影响，PDV 的正相位具有更高的 SSW 频率。这种 PDV 影响是由 PDV 异常与对流层驻波的相长干扰所介导的。相反，AMV 的主要作用是调制对 SSW 的对流层响应，这一发现可用于预测 SSW 的对流层指纹。