Atlantic Niño–ENSO关系的年代际变化及其影响因子:基于CESM1长期模拟的研究  

Inter-decadal Variation in Atlantic Niño–ENSO Relationship and Its Influencing Mechanisms:A Study Based on Long-Term CESM1 Simulation

作　　者：陶淑琳 陈林[1] 姜蕾杉 王然 王阔[2] 邢雯 TAO Shulin;CHEN Lin;JIANG Leishan;WANG Ran;WANG Kuo;XING Wen(Key Laboratory of Meteorological Disaster,Ministry of Education(KLME)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD),Nanjing University of Information Science and Technology,Nanjing 210044;Zhejiang Climate Center,Hangzhou 310017;State Key Laboratory of Tropical Oceanography,South China Sea Institute of Oceanology(SCSIO),Chinese Academy of Sciences(CAS),Guangzhou 510301)

机构地区：[1]南京信息工程大学气象灾害教育部重点实验室/气象灾害预报预警与评估协同创新中心/气候与环境变化国际合作联合实验室,南京210044 [2]浙江省气候中心,杭州310017 [3]中国科学院南海海洋研究所热带海洋环境国家重点实验室,广州510301

出　　处：《大气科学》2024年第6期2215-2234,共20页Chinese Journal of Atmospheric Sciences

基　　金：江苏省优秀青年基金项目BK20230061;国家自然科学基金项目42305021;江苏省青年基金项目SBK2023043823;热带海洋环境国家重点实验室(中国科学院南海海洋研究所)开放课题LTO_(2)324。

摘　　要：三大洋相互作用是当前国际前沿的热点问题之一,近年来大西洋和印度洋对太平洋气候变率的影响得到了广泛的关注,其中热带大西洋主要年际变率Atlantic Niño/Atlantic Niña(大西洋尼诺/尼娜)对El Niño–Southern Oscillation(ENSO)的发展演变具有不可忽视的影响。观测结果表明夏季大西洋尼诺/尼娜与随后冬季ENSO的负相关关系(以下简称“Atlantic Niño–ENSO关系”)并非一直显著,而是表现出了年代际差异,然而关于影响二者关系年代际差异的关键物理因子尚不清楚。本文基于观测资料和地球系统模式(CESM1)长期模拟资料分析了影响Atlantic Niño–ENSO关系变化的关键因子,得到以下主要结论:(1)夏秋印度洋偶极子(IOD)是调控Atlantic Niño–ENSO二者关系密切与否的重要因子之一。当大西洋尼诺(尼娜)激发出热带大西洋—太平洋异常沃克环流的同时,负IOD(正IOD)可以激发热带印度洋—太平洋异常沃克环流,对应的下沉支(上升支)加强了大西洋尼诺(尼娜)引发的太平洋异常沃克环流下沉支(上升支),最终造成赤道太平洋低层东风(西风)异常,促进了随后拉尼娜(厄尔尼诺)事件的发生发展。(2)ENSO发展前期的夏季太平洋海洋热容量初始状态也是调制大西洋尼诺/尼娜能否影响随后ENSO事件发生发展的另一关键因子。当大西洋尼诺(尼娜)发生时,若同期赤道太平洋处于“放电”(“充电”)状态,则更有利于随后拉尼娜(厄尔尼诺)事件的形成。值得指出的是,夏秋季IOD与夏季太平洋海洋热容量初始状态这两个关键因子相互独立,二者对Atlantic Niño–ENSO关系的调制作用相当。总之,在关注热带大西洋影响太平洋气候变率的时候,须同时考虑印度洋特别是IOD信号的影响以及热带太平洋自身海洋初始态影响。由于观测资料长度有限,该研究基于长时间模拟资料所得的结论可作为观测结果的补充,有助于增�Currently,tropical inter-basin interactions are a cutting-edge research topic worldwide,and the impacts of the Atlantic and Indian Oceans on Pacific Ocean climate variability have garnered extensive attention.Atlantic Niño,the dominant interannual mode in the tropical Atlantic,plays an indispensable role in the development and evolution of El Niño–Southern Oscillation(ENSO).Observation results show that the relationship between Atlantic Niño in boreal summer and ENSO in subsequent winter(hereinafter referred to as the Atlantic Niño–ENSO relationship)is nonstationary and exhibits an interdecadal variation feature.However,the key physical factors affecting the interdecadal variations in the Atlantic Niño–ENSO relationship remain unclear.Through observations and the long-term Community Earth System Model 1(CESM1)simulation archive,this study analyzes the key factors affecting this relationship and draws the following conclusions.(1)The Indian Ocean dipole(IOD)signals in summer and autumn are an important factor regulating the Atlantic Niño–ENSO relationship.Specifically,when Atlantic Niño stimulates abnormal Walker circulation in the tropical Atlantic–Pacific Ocean,a negative IOD can stimulate abnormal Walker circulation in the tropical Indo-Pacific Ocean,whose sinking branch strengthens the original sinking branch of the abnormal Walker circulation in the Atlantic–Pacific Ocean.Such a strengthened sinking branch can induce anomalous,low-level easterly winds in the equatorial Pacific Ocean and thus promote the development of the La Niña event in subsequent seasons and vice versa.(2)The initial heat content state of the Pacific Ocean is another key factor that modulates the influence of Atlantic Niño on ENSO.Atlantic Niño occurring while the equatorial Pacific Ocean is in a“discharged”state(meaning that the zonal mean equatorial thermocline is shallower than normal)facilitates the subsequent formation of La Niña and vice versa.Noteworthily,these two key factors,namely the IOD signals and in

关 键 词：大西洋尼诺 ENSO 跨洋盆相互作用 热带海气相互作用 

分 类 号：P467[天文地球—大气科学及气象学]