The ENSO amplitude forecast model based on online filtering scheme and its prediction for the 2023/2024 El Ni?o event
Instead of Lanczos filtering,this paper utilizes an online filtering scheme to compute the real-time accumulated high-frequency wind index and construct the ENSO amplitude forecast model.Results show that the online-filtered high-frequency wind events exhibit similar spatiotemporal features to the original method.These high-frequency atmospheric conditions,along with the relatively slower oceanic recharged/discharged process,play important roles in determining the ENSO amplitude at the peak phase,and exhibit notable spatial asymmetry for El Nino and La Niña events.La Niña amplitude at the peak season is closely associated with the accumulated Easterly Wind Events(EWEs)over the equatorial western Pacific from the previous December to April and the discharged state in the western equatorial Pacific during February.In contrast,the amplitude of El Niño events is sensitive to the accumulated Westerly Wind Events(WWEs)over the eastern equatorial Pacific and the recharged state extending from the equatorial western to central Pacific.By utilizing these asymmetric oceanic and atmospheric preconditions of El Nino and La Nina events,a statistical model was established to accurately forecast the ENSO amplitude,exhibiting comparable prediction skills and robustness to the original model based on Lanczos filtering.The newly-established model predict that the 2023/2024 El Niño will be a strong event with the magnitude of nearly 1.9℃.
万方数据
维普
