Predictability of the Chile Niño/Niña

Abstract

AbstractThe recently discovered Chile Niño/Niña is an intrinsic coupled climate mode in the southeast Pacific, which influences both regional climate and marine ecosystem. Using Scale Interaction Experiment‐Frontier version 2 seasonal prediction system, it is shown that the Chile Niño/Niña can be skillfully predicted up to 3‐month lead. Although the occurrences and related climate impacts of the Chile Niño/Niña are captured by the prediction system, the predicted magnitudes are weaker than observations in the ensemble mean. Further analyses of the inter‐member relationships indicate that the Chile Niño/Niña predictability depends on how well the coastal ocean‐atmosphere‐land positive feedback among alongshore surface winds, coastal upwelling and the sea surface temperature anomalies is captured. The insufficient reproduction of this essential feedback is responsible for the underestimated magnitude. Therefore, accurately predicting the Chile Niño/Niña remains a challenge. Improving model resolution and ensemble size may be a key to enhancing prediction skills of the coastal climate modes along the eastern boundary upwelling systems.