Predictable equatorial Atlantic variability from atmospheric convection-ocean coupling

Abstract

The Atlantic Niño exerts profound impacts on regional and global atmospheric circulation and climate, and on equatorial Atlantic biogeochemistry and ecosystems. However, the mode’s prediction remains a challenge which has been partly attributed to weak atmosphere-ocean coupling in the region. Here we introduce a framework that enhances the detection of the coupling between meridional migrations of atmospheric deep convection and zonal thermocline feedback. This approach reveals high predictive skill in a 196-member seasonal prediction ensemble, demonstrating robust predictability at 1–5-month forecast initialization lead times. The coupled mode is strongly correlated with land-precipitation variability across the tropics. The predictive skill largely originates in the Atlantic Ocean and is uncorrelated with El Niño Southern Oscillation in the Pacific, the leading mode of interannual climate variability globally. These skillful predictions raise hopes for enabled action in advance to avoid the most severe societal impacts in the affected countries.