Impacts of the annual cycle of background SST in the tropical Pacific on the phase and amplitude of ENSO

作     者：Song Jiang Congwen Zhu Ning Jiang 

作者机构：State Key Laboratory of Severe Weather(LASW)Chinese Academy of Meteorological SciencesBeijingChina College of Earth and Planetary SciencesUniversity of Chinese Academy of SciencesBeijingChina 

出 版 物：《Atmospheric and Oceanic Science Letters》 (大气和海洋科学快报（英文版）)

年 卷 期：2025年第18卷第1期

页      面：12-17页

核心收录：

学科分类：07[理学] 0707[理学-海洋科学] 

基　　金：jointly supported by the National Natural Science Foundation of China [grant numbers U2242205 and 41830969] the S&T Development Fund of CAMS [grant number 2023KJ036] the Basic Scientific Research and Operation Foundation of CAMS [grant number 2023Z018] 

主　　题：Annual cycle SST anomaly Antisymmetric mode ENSO 

摘      要：The dominant annual cycle of sea surface temperature(SST)in the tropical Pacific exhibits an antisymmetric mode,which explains 83.4%total variance,and serves as a background of El Niño-Southern Oscillation(ENSO).However,there is no consensus yet on its anomalous impacts on the phase and amplitude of *** on data during 1982-2022,results show that anomalies of the antisymmetric mode can affect the evolution of ENSO on the interannual scale via Bjerknes feedback,in which the positive(negative)phase of the antisymmetric mode can strengthen El Niño(La Niña)in boreal winter via an earlier(delayed)seasonal cycle transition and larger(smaller)annual *** magnitude of the SST anomalies in the equatorial eastern Pacific can reach more than±0.3◦C,regulated by the changes in the antisymmetric mode based on random sensitivity *** reveal the spatial pattern of the annual cycle associated with the seasonal phase-locking of ENSO evolution and provide new insight into the impact of the annual cycle of background SST on ENSO,which possibly carries important implications for forecasting ENSO.