Sea Surface Temperature Anomalies in the Western Indian Ocean as a Trigger for Atlantic Niño Events
Huaxia Liao, Chunzai Wang
Abstract
Abstract Pacific El Niño and Atlantic Niño events represent prominent interannual climate fluctuations in tropical regions. Both of them have considerable impacts on the climate system and human livelihoods. The interaction between the Pacific El Niño and Atlantic Niño has received wide attention. Here, we use observations and numerical model experiments to show a new trigger from the western Indian Ocean (WIO) that can serve as a predictor for Atlantic Niño events. The warm sea surface temperature (SST) anomalies in the WIO alter the Walker circulation in the boreal winter, weaken the surface trade winds over the tropical Atlantic and favor an Atlantic Niño in the subsequent summer. These inter‐basin processes also affect the interaction between the Pacific El Niño and Atlantic Niño. The results imply that a better simulation of the WIO SST and its teleconnection may help to forecast Atlantic Niño events.