Nonlinearity Modulating Intensities and Spatial Structures of Central Pacific and Eastern Pacific El Nio Events

作     者：Wansuo DUAN Chaoming HUANG Hui XU 

作者机构：State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG) Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China University of Chinese Academy of Sciences Beijing 100049 China 

出 版 物：《Advances in Atmospheric Sciences》 (大气科学进展（英文版）)

年 卷 期：2017年第34卷第6期

页      面：737-756页

核心收录：

学科分类：07[理学] 070601[理学-气象学] 0706[理学-大气科学] 0816[工学-测绘科学与技术] 0825[工学-航空宇航科学与技术] 

基　　金：National Natural Science Foundation of China [41525017  41230420  41476015] 

主　　题：E1 Nifio diversity nonlinearity intensity spatial structures nonlinear temperature advection 

摘      要：This paper compares data from linearized and nonlinear Zebiak-Cane model, as constrained by observed sea surface temperature anomaly （SSTA）, in simulating central Pacific （CP） and eastern Pacific （EP） E1 Nino. The difference between the temperature advections （determined by subtracting those of the linearized model from those of the nonlinear model）, referred to here as the nonlinearly induced temperature advection change （NTA）, is analyzed. The results demonstrate that the NTA records warming in the central equatorial Pacific during CP E1 Nino and makes fewer contributions to the structural distinctions of the CP E1 Nino, whereas it records warming in the eastern equatorial Pacific during EP E1 Nino, and thus significantly promotes EP E1 Nino during E1 Nino-type selection. The NTA for CP and EP E1 Nino varies in its amplitude, and is smaller in CP E1 Nino than it is in EP E1 Nino. These results demonstrate that CP E1 Nino are weakly modulated by small intensities of NTA, and may be controlled by weak nonlinearity; whereas, EP E1 Nino are significantly enhanced by large amplitudes of NTA, and are therefore likely to be modulated by relatively strong nonlinearity. These data could explain why CP E1 Nino are weaker than EP E1 Nino. Because the NTA for CP and EP E1 Nino differs in spatial structures and intensities, as well as their roles within different E1 Nino modes, the diversity of E1 Nino may be closely related to changes in the nonlinear characteristics of the tropical Pacific.