An Asymptotic Expansion for the Recharge–Discharge Model of ENSO
An Asymptotic Expansion for the Recharge–Discharge Model of ENSO
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DOI：
10.1175/jpo-d-12-0161.1
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发表时间：
2013-07
影响因子：
3.5
通讯作者：
S. Thual;B. Dewitte;N. Ayoub;O. Thual
中科院分区：
文献类型：
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作者：
S. Thual;B. Dewitte;N. Ayoub;O. Thual
摘要 赤道太平洋厄尔尼诺-南方涛动（ENSO）的动态很大程度上与年际和盆地尺度的温跃层缓慢调整有关。除其他外，这种调整涉及风应力强迫下的赤道波的快速传播和反射。使用低频近似提出了长波方程的简单且直接的渐近展开。渐近展开在傅里叶空间中进行，仅保留最大尺度的最严重的赤道长波和斜压模态，并考虑摩擦和边界反射引起的小耗散。这导致温跃层对风应力强迫响应的渐近模型，本质上是 ENSO 补给-排放模型的海洋部分。渐近模型是非启发式的，并且与先前研究中分散的一些基本结果广泛一致。温跃层变异性分为倾斜的“倾斜模式”，可调整...
AbstractThe dynamics of El Nino–Southern Oscillation (ENSO) in the equatorial Pacific Ocean are largely associated with the slow thermocline adjustment at interannual and basin scales. This adjustment involves, among other things, the fast propagation and reflection of equatorial waves by wind stress forcing. A simple and straightforward asymptotic expansion of the long-wave equations is proposed using the low-frequency approximation. The asymptotic expansion is performed in Fourier space, retaining only the gravest equatorial long waves and baroclinic modes with the largest scale, and considering small dissipation by friction and boundary reflections. This leads to an asymptotic model for the thermocline response to wind stress forcing, which is in essence the ocean component of the recharge–discharge model of ENSO. The asymptotic model is nonheuristic and in broad agreement with some essential results scattered in previous studies. Thermocline variability is divided into a sloping “Tilt mode” that adjus...