The influences of the tropical Indian and Atlantic oceans on the development of El Niño Southern Oscillation (ENSO), especially regarding super El Niño events, have been a subject of debate. In particular, several studies argue that these cross-basin influences may be mere statistical artifacts resulting from the high auto-correlation of ENSO. To clarify this issue, we conduct a series of perfect model hindcast experiments to untangle the individual and synergistic effects of the tropical Indian and Atlantic oceans. Our results clearly demonstrate that without these cross-basin effects, the Pacific warming would rarely reach super El Niño level. Specifically, the individual effect of the Indian Ocean efficiently enhances the development of super El Niño events. In contrast, the Atlantic’s effect is initially limited because it fails to establish the Bjerknes feedback in the Pacific. However, when coupled with the Indian Ocean, the Atlantic’s effect becomes more pronounced as it is amplified by the Bjerknes feedback established by the Indian Ocean.

中文翻译：

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耦合是热带印度洋和大西洋助长超级厄尔尼诺现象的关键


热带印度洋和大西洋对厄尔尼诺南方涛动 （ENSO） 发展的影响，尤其是关于超级厄尔尼诺事件的影响，一直是一个争论的话题。特别是，一些研究认为，这些跨流域影响可能只是由于 ENSO 的高度自相关而导致的统计伪影。为了澄清这个问题，我们进行了一系列完美的模型后报实验，以解开热带印度洋和大西洋的单独和协同效应。我们的结果清楚地表明，如果没有这些跨流域效应，太平洋变暖很少会达到超级厄尔尼诺水平。具体来说，印度洋的个体效应有效地促进了超级厄尔尼诺事件的发展。相比之下，大西洋的影响最初是有限的，因为它未能在太平洋建立 Bjerknes 反馈。然而，当与印度洋相结合时，大西洋的影响变得更加明显，因为它被印度洋建立的 Bjerknes 反馈放大了。