Multi-Season Lead Prediction of Atlantic Niño Facilitated by Pacific Ocean Precursors

Abstract

The boreal summer Atlantic Niño, the dominant mode of interannual climate variability in the equatorial Atlantic, exerts profound effects on local ecosystems and broader climate patterns, yet its prediction remains a long-standing challenge. The short lifecycle of the Atlantic Niño and the lack of precursor signals beyond about one season lead time have hindered the development of forecasts with useful accuracy and lead time. In this study, we propose a new approach to Atlantic Niño forecasting that extends beyond the Atlantic region by incorporating longer-lasting precursors in the Pacific associated with El Niño-Southern Oscillation events. Using this prediction framework, we can hindcast the Atlantic Niño with skill up to three seasons in advance. Our results highlight the critical role of inter-basin interactions in shaping regional and global climate patterns, and provide new hope for improving seasonal climate prediction capabilities in the tropical Atlantic. Plain Summary Despite extensive efforts made by the climate research community, the equatorial Atlantic region, in particular the Atlantic Niño phenomenon, consistently demonstrates poor seasonal forecasting capabilities. In this study, we propose a new approach to Atlantic Niño forecasting by using longer-lasting precursors in the Pacific. The new prediction framework enables skillful prediction of the boreal summer Atlantic Niño events up to three seasons in advance. The results of our study have the possibility to reduce the existing gap in seasonal prediction for the equatorial Atlantic region by leveraging inter-basin information, particularly benefitting vulnerable communities in the tropical Atlantic basin.