资源环境科技发展态势分析平台

The El Niño Southern Oscillation (ENSO) is a mode of internal climate variability with far-reaching impacts. Here, we consider an important aspect of ENSO behavior: the diversity in the persistence of El Niño events. We examine the occurrence of multi-year El Niño events in instrumental observations, a suite of global climate model simulations of the last millennium, and paleoclimate archives. We find evidence of multi-year El Niño events in all data sources considered, with a wide range of variability in the frequency of such events across and within the individual sources. Although scarce over the relatively brief satellite era, multi-year El Niño events are often associated with the warmest El Niño events in observations and most models. Furthermore, we show that multi-year El Niño events augment the persistence of associated hydroclimate anomalies, which may compound the impacts on vulnerable economies and ecosystems within and beyond the tropical Pacific sector.