Convectively Coupled Equatorial Waves. Part II: Propagation Characteristics
Convectively Coupled Equatorial Waves. Part II: Propagation Characteristics
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DOI：
10.1175/jas4018.1
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发表时间：
2007-10
影响因子：
3.1
通讯作者：
Gui‐Ying Yang;B. Hoskins;J. Slingo
中科院分区：
文献类型：
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作者：
Gui‐Ying Yang;B. Hoskins;J. Slingo
在第1部分对赤道对流耦合波的水平和垂直结构进行描述的基础上，本文对赤道对流耦合波的传播特性进行了研究。采用线性滞后回归计算其复合演化过程，采用Radon变换技术计算其相速度。结果表明，具有对流耦合的相干波结构一般存在1 ~ 2周左右。典型的纬向波数为6-8，波长为经度42°-64°，典型周期为4-8天。对流耦合开尔文波的东相速度在10 ~ 17 m s−1之间。耦合的混合罗斯比-重力波西向相速度在10 ~ 15 m s−1之间，耦合的n = 1罗斯比波西向相速度在7 ~ 9 m s−1之间。研究发现，对流对相速度产生较强的垂直耦合，环境流的多普勒频移对相速度有一定的影响。有进一步的证据表明，一些波浪……
Abstract Following the description of the horizontal and vertical structures of convectively coupled equatorial waves presented in Part I, here their propagation characteristics are investigated. Linear lagged regressions are used to produce their composite evolution, and the Radon transform technique is used to calculate their phase speeds. It is shown that coherent wave structures with convective coupling generally exist for about 1–2 weeks. Typical zonal wavenumbers are 6–8, wavelengths are 42°–64° of longitude, and typical periods are 4–8 days. The eastward phase speed of convectively coupled Kelvin waves is between 10 and 17 m s−1. The westward phase speed of the coupled mixed Rossby–gravity wave is between 10 and 15 m s−1, and the westward phase speed of the coupled n = 1 Rossby wave is between 7 and 9 m s−1. It is found that convection can produce stronger vertical coupling of phase speeds, and Doppler shifting by the ambient flow can modify phase speeds. There is further evidence that some waves t...