There is a strong association between canonical El Niño and a wet Greater Horn of Africa (GHA) short rains. However, the link with Modoki El Niño events appears to be significantly weaker. In order to understand this, we present an analysis of observational data and idealised climate model experiments. Idealised atmospheric simulations isolate the direct influence of Pacific heating on the GHA and reveal that neither the longitudinal position nor the observed weaker magnitude of Modoki Pacific heating anomalies can explain the difference in teleconnections. The direct effect of canonical or Modoki Pacific heating patterns on the GHA is similar and neither reproduces the structure of the full GHA teleconnection: they both generate a wet‐dry dipole over the GHA instead of large‐scale single‐signed wet anomalies. Our results indicate that the strong canonical ENSO influence on GHA is indirect, mediated through its strong relationship with the Indian Ocean Dipole (IOD). By contrast, Modoki ENSO is uncorrelated with the IOD, resulting in weak teleconnection to GHA. Understanding these differences aids seasonal forecast interpretation, whilst their representation in models is likely a prerequisite for making accurate projections of changes in extremes over the GHA and beyond.

中文翻译：

---

将ENSO的不同风味与大非洲之角短雨联系起来的因果关系

规范的厄尔尼诺现象与潮湿的大非洲之角（GHA）短雨之间有很强的联系。但是，与莫多基·厄尔尼诺事件的联系似乎很弱。为了理解这一点，我们提出了对观测数据的分析和理想的气候模型实验。理想的大气模拟将太平洋加热对GHA的直接影响隔离开来，并揭示出纵向位置或Modoki太平洋加热异常的观测到的较弱幅度都不能解释遥相关的差异。规范或Modoki Pacific加热模式对GHA的直接影响是相似的，并且都没有再现完整的GHA遥连接的结构：它们都在GHA上产生干湿偶极子，而不是大规模的单符号湿异常。我们的结果表明，ENSO对GHA的强烈规范影响是间接的，是通过其与印度洋偶极子（IOD）的强烈关系来介导的。相比之下，Modoki ENSO与IOD不相关，导致与GHA的远程连接较弱。理解这些差异有助于季节性预测的解释，而它们在模型中的表示可能是对GHA及其以上极端变化的准确预测的先决条件。