Impact of Equatorial Atlantic Variability on ENSO Predictive Skill

El Niño–Southern Oscillation (ENSO) is a key mode of climate variability with worldwide climate impacts. Recent studies have highlighted the impact of other tropical oceans on its variability. In particular, observations have demonstrated that summer Atlantic Niños (Niñas) favor the development of Pacific Niñas (Niños) the following winter, but it is unclear how well climate models capture this teleconnection and its role in defining the seasonal predictive skill of ENSO. Here we use, for the first time, an ensemble of seasonal forecast systems to demonstrate that a proper representation of Tropical Atlantic variability and its teleconnection mechanism with the Pacific relates to enhanced predictive capacity of autumn/winter ENSO. An additional sensitivity study further hows that correcting wind-related SST biases in Equatorial Atlantic improves the forecast skill both locally and in the Tropical Pacific, boosting ENSO skill and in particular of the strongest events. This study thus emphasizes that new efforts to overcome systematic biases in Tropical Atlantic, a long standing problem in climate models, can foster predictive skill in the region and beyond, through the global impacts of ENSO.