Two Leading ENSO Modes and El Niño Types in the Zebiak-Cane Model
Two Leading ENSO Modes and El Niño Types in the Zebiak-Cane Model
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Zebiak-Cane 模型中的两种领先 ENSO 模态和厄尔尼诺类型
DOI：
10.1175/jcli-d-17-0469.1
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发表时间：
2017-12
影响因子：
4.9
通讯作者：
Fei-Fei Jin
中科院分区：
文献类型：
--
作者：
Ruihuang Xie;Fei-Fei Jin
现代仪器记录显示，厄尔尼诺事件在空间模式和时间演变上有所不同。人们试图将它们大致归类为两种主要类型：东太平洋(冷舌头)和中太平洋(暖池)厄尔尼诺事件。在这项研究中，我们使用一种改进的Zebiak-Cane(MZC)耦合模式来研究这两类厄尔尼诺事件的动力学。我们对模式进行了线性特征分析，发现有两个主要的ENSO(厄尔尼诺-南方涛动)模，它们的SST谱与两种类型的厄尔尼诺相似，因此我们称它们为EP和CP ENSO模。这两种模式敏感地依赖于平均态的变化。热量收支分析表明，EP(CP)模以温跃层(纬向平流)反馈为主。因此，弱(强)平均风应力和深(浅)平均温跃层更倾向于EP(CP)ENSO模式，因为在这种平均状态下温跃层(纬向平流)反馈相对占优势。与线性稳定性分析相一致的是，在非线性模拟中，CP/EP厄尔尼诺事件的发生率一般向线性CP ENSO模增长率较高的区域增加。我们的分析表明，在MZC模式中模拟的两种厄尔尼诺现象是由两种主要ENSO模的共存造成的。该模型的结果可以为观测到的ENSO分集提供一种合理的情景。
Modern instrumental records reveal that El Niño events differ in their spatial patterns and temporal evolutions. Attempts have been made to categorize them roughly into two main types: eastern Pacific (EP; or cold tongue) and central Pacific (CP; or warm pool) El Niño events. In this study, we use a modified version of Zebiak-Cane (MZC) coupled model to examine the dynamics of these two types of El Nino events. We conducted linear eigen-analysis of the model to show that there are two leading ENSO (El Niño-Southern Oscillation) modes with their SST patterns resembling those of two types of El Niño. Thus, we refer them as the EP and CP ENSO modes. These two modes sensitively depend on the changes in the mean states. The heat budget analyses demonstrate that the EP (CP) mode is dominated by thermocline (zonal advective) feedback. Therefore, weak (strong) mean wind stress and deep (shallow) mean thermocline prefers the EP (CP) ENSO mode because of the relatively dominance of thermocline (zonal advective) feedback under such mean state. Consistent with the linear stability analysis, the occurrence ratio of CP/EP El Niño events in the nonlinear simulations generally increases towards the regime where the linear CP ENSO mode has relatively higher growth rate. Our analyses suggest that the co-existence of two leading ENSO modes is responsible for two types of El Niño simulated in the MZC model. This model result may provide a plausible scenario for the observed ENSO diversity.
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DOI：
10.1073/pnas.1620766114
发表时间：
2017-01
期刊：
Proceedings of the National Academy of Sciences
影响因子：
--
作者：
N. Chen;A. Majda
通讯作者：
N. Chen;A. Majda
影响因子：
3.2
作者：
E. Kalnay;A. Dalcher
通讯作者：
E. Kalnay;A. Dalcher
影响因子：
3.1
作者：
K. Trenberth;Shyh-C. Chen
通讯作者：
K. Trenberth;Shyh-C. Chen
影响因子：
8
作者：
Capotondi, Antonietta;Wittenberg, Andrew T.;Yeh, Sang-Wook
通讯作者：
Yeh, Sang-Wook
影响因子：
5.2
作者：
S. An;F. Jin
通讯作者：
S. An;F. Jin