资源环境科技发展态势分析平台

The warm center of the 2015/2016 extreme El Nino was located further to the west compared to previous extreme events, causing vastly different social-economic impacts. Though many studies investigated ocean-atmosphere couplings responsible for its large magnitude, the dynamics that govern the unique structure of the event remain elusive. Here we show that a local ocean-atmosphere feedback among convection-induced surface winds, oceanic upwelling and sea surface temperature in the far-eastern Pacific, resulted in a boreal summer cooling tendency along the South American coast. It canceled warming in the far-eastern equatorial Pacific that would otherwise develop, leading to the distinctive anomaly pattern of the 2015/2016 El Nino. These processes were initially triggered by the leftover anomalous warm sea surface temperature and positive moist static energy over the northeastern tropical Pacific in the following boreal spring of the 2014 warm event.