Spectrum Analysis of Symmetric and Antisymmetric Equatorial Waves
Spectrum Analysis of Symmetric and Antisymmetric Equatorial Waves
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对称和反对称赤道波的频谱分析
DOI：
10.2151/jmsj1965.48.4_331
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发表时间：
1970
影响因子：
3.1
通讯作者：
M. Murakami
中科院分区：
文献类型：
--
作者：
M. Yanai;M. Murakami
本文利用分布在赤道两侧的四个太平洋台站的时间序列资料，将大尺度赤道波分为ODD型和EVEN型。通过对赤道对称和反对称风分量的频谱分析，至少分离出8个不同的波。大部分ODD模式波向东传播，只表现出纬向风振荡，表明它们是开尔文波。有两种ODD模式波可以与Rossby波识别，因为它们相对于空气向西传播。包括柳井和丸山（Maruyama，1966）发现的4 ~ 5日波在内的所有偶模波（似Rossby重力混合波）都向西移动。的垂直振幅分布和垂直相位传播检查每个孤立波。所有波都在约12-14 km的水平处显示出最大谱密度，相线的倾斜表明波能在最大谱密度水平上方向上传播，而在该水平下方向下传播。有些波具有很大的相线倾角，即。例如，垂直波长很短。利用两对台站的观测水平波长与根据观测周期和垂直波长用Matsuno（1966）和Lindzen（1967）的频率方程计算的结果进行了比较。
An attempt is made to separate large-scale equatorial waves into the ODD-mode and the EVEN-mode waves using time series data of four Pacific stations which are located nearly symmetrically on both sides of the equator. At least eight distinct waves are isolated by the spectrum analysis of symmetric and antisymmetric components of winds with respect to the equator. Most of the ODD-mode waves propagate eastward and exhibit only zonal wind oscillations indicating that they are Kelvin waves. There are two ODD-mode waves that may be identified with Rossby waves, because they show westward propagation relative to the air. All the EVEN-mode waves (seemingly the mixed Rossby-gravity waves) including the 4to 5-day waves found by Yanai and Maruyama (1966) move westward. The vertical amplitude distribution and the vertical phase propagation are examined for each of the isolated waves. All the waves show maximum spectral density at about 12-14 km levels and the inclination of phase lines indicates upward propagation of wave energy above the level of maximum spectral density and downward energypropagation below the level. Some waves have very large inclination of phase lines, i. e., very short vertical wavelengths. The observed horizontal wavelength by use of two pairs of stations is compared with the calculation using the frequency equation of Matsuno (1966) and Lindzen (1967) based on the observed period and vertical wavelength.