Simulating Eastern- and Central-Pacific Type ENSO Using a Simple Coupled Model
Simulating Eastern- and Central-Pacific Type ENSO Using a Simple Coupled Model
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使用简单耦合模型模拟东太平洋和中太平洋型 ENSO
DOI：
10.1007/s00376-017-7209-9
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发表时间：
2018-06-01
影响因子：
5.8
通讯作者：
Zheng, Fei
中科院分区：
文献类型：
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作者：
Fang, Xianghui;Zheng, Fei
在捕捉真实的中太平洋厄尔尼诺结构时，最先进的大气环流模式（GCM）存在严重的偏差。同时，许多观测分析强调，温跃层（TH）反馈和纬向平流（ZA）反馈分别在东太平洋（EP）和太平洋厄尔尼诺南方涛动（ENSO）的发展中起主导作用。本文利用一个简单的线性海气耦合模式，对这两种类型的厄尔尼诺现象进行了研究，该模式能准确地描述赤道太平洋TH和ZA反馈的强度分布。结果表明，如果关闭TH反馈，保留ZA反馈作为唯一的正反馈，模型可以再现CP ENSO的主要特征，证实了ZA反馈在CP ENSO发展中所发挥的主导作用。进一步的实验表明，通过简单的非线性控制方法，简单的线性海气耦合模式可以成功地捕捉到许多ENSO特征，包括CP和EP El Nio的存在以及El Nio和La Nia之间的不对称性。这些分析表明，准确地描述气候海表温度分布和相关的ZA反馈，这是严重的偏差在GCM的主题，是非常重要的，在模拟一个现实的CP厄尔尼诺。
Severe biases exist in state-of-the-art general circulation models (GCMs) in capturing realistic central-Pacific (CP) El Nio structures. At the same time, many observational analyses have emphasized that thermocline (TH) feedback and zonal advective (ZA) feedback play dominant roles in the development of eastern-Pacific (EP) and CP El Nio-Southern Oscillation (ENSO), respectively. In this work, a simple linear air-sea coupled model, which can accurately depict the strength distribution of the TH and ZA feedbacks in the equatorial Pacific, is used to investigate these two types of El Nio. The results indicate that the model can reproduce the main characteristics of CP ENSO if the TH feedback is switched off and the ZA feedback is retained as the only positive feedback, confirming the dominant role played by ZA feedback in the development of CP ENSO. Further experiments indicate that, through a simple nonlinear control approach, many ENSO characteristics, including the existence of both CP and EP El Nio and the asymmetries between El Nio and La Nia, can be successfully captured using the simple linear air-sea coupled model. These analyses indicate that an accurate depiction of the climatological sea surface temperature distribution and the related ZA feedback, which are the subject of severe biases in GCMs, is very important in simulating a realistic CP El Nio.