El Nino and La Nina amplitude asymmetry caused by atmospheric feedbacks
El Nino and La Nina amplitude asymmetry caused by atmospheric feedbacks
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DOI：
10.1029/2010gl044444
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发表时间：
2010-09-16
影响因子：
5.2
通讯作者：
Dommenget, Dietmar
中科院分区：
文献类型：
--
作者：
Frauen, Claudia;Dommenget, Dietmar
热带太平洋海表温度（SST）的年际变化具有不对称性，较强的正事件，厄尔尼诺和较弱的负事件，拉尼娜，这通常归因于海洋过程。在这里，我们提出的证据，从一个新的混合耦合模式的不对称性和季节性的厄尔尼诺现象可以引起的非线性和季节性变化的大气反馈。该模式包括ECHAM 5全球大气环流模式（GCM）耦合到二维厄尔尼诺线性补给振荡器海洋模式在热带太平洋和混合层海洋其他地方。尽管该模型过于简单，通过构造，海洋动力学的线性表示，它能够模拟厄尔尼诺的主要统计特征，包括周期，季节性，偏度和峰度。模式分析表明，纬向风应力与海温的非线性关系是造成厄尔尼诺-拉尼娜不对称的原因。引文：Frauen，C.，和D. Dommenget（2010），El Nino and La Nina amplitude asymmetry caused by atmospheric feedbacks，Geophys.保留信函：37，L18801，doi：10.1029/2010GL044444。
Interannual variability of tropical Pacific sea surface temperatures (SST) has an asymmetry with stronger positive events, El Nino, and weaker negative events, La Nina, which is generally attributed to processes in the ocean. Here we present evidence from a new hybrid coupled model that the asymmetry and seasonality of El Nino can be caused by nonlinear and seasonally varying atmospheric feedbacks. The model consists of the ECHAM5 global atmospheric general circulation model (GCM) coupled to the 2-dimensional El Nino linear recharge oscillator ocean model in the tropical Pacific and a mixed layer ocean elsewhere. Despite the models simplistic and, by construction, linear representation of the ocean dynamics, it is able to simulate the main statistical features of El Nino including period, seasonality, skewness, and kurtosis. Analyses of the model show that a nonlinear relationship between zonal wind stress and SST is causing the El Nino-La Nina asymmetry. Citation: Frauen, C., and D. Dommenget (2010), El Nino and La Nina amplitude asymmetry caused by atmospheric feedbacks, Geophys. Res. Lett., 37, L18801, doi:10.1029/2010GL044444.