Seasonal-to-decadal prediction of El Niño–Southern Oscillation and Pacific Decadal Oscillation

Abstract The growing demand for skillful near-term climate prediction encourages an improved prediction of low-frequency sea surface temperature (SST) variabilities such as the El Niño-Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO). This study assesses their seasonal-to-decadal prediction skills using large ensembles of the Coupled Model Intercomparison Project phases 5 and 6 retrospective decadal predictions. A multi-model ensemble reforecast successfully predicts ENSO over a year in advance. While its seasonal prediction skill in the following spring and summer is achieved by multi-model ensemble averaging of relatively smaller ensemble members, the multi-year prediction of winter ENSO needs a larger ensemble size. The PDO is significantly predicted at a lead time of five-to-nine years but such a long-lead prediction is sourced from external radiative forcing instead…