Waves on the beta-plane over sparse topography
Waves on the beta-plane over sparse topography
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稀疏地形上 β 平面上的波
DOI：
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发表时间：
2000
影响因子：
3.7
通讯作者：
E. Benilov
中科院分区：
文献类型：
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作者：
E. Benilov
本文讨论地形上贝塔平面上的线性波。主要假设地形由孤立的径向对称不规则性(随机或周期性)组成，使得它们的特征半径远远小于它们之间的距离。这种近似可以得到波模频率的色散关系；为了检验这些色散关系的性质，我们考虑了一种特殊的情况，其中底部不规则性是不同高度和半径的柱体。结果表明，如果所有不规则点的高度h相同，则存在两个地形模和一个Rossby模。其中一个地形模式的频率被锁定在频带内(−fh/2h0，fh/2h0)，其中f是科里奥利参数，H0是海洋的平均深度。另一种地形模式和正压Rossby模式的频率分别在频带上方和下方被“锁定”。证明了当圆柱高度分布在一定范围内(−H0，H0)时，在该区间(−FH0/2H0，FH0/2H0)内不存在简谐振型。地形模式和罗斯比模式被“推”出了“禁止”频段。
This paper deals with linear waves on the beta-plane over topography. The main assumption is that the topography consists of isolated radially symmetric irregularities (random or periodic), such that their characteristic radii are much smaller than the distances between them. This approximation allows one to obtain the dispersion relation for the frequency of wave modes; and in order to examine the properties of those, we consider a particular case where bottom irregularities are cylinders of various heights and radii. It is demonstrated that if all irregularities are of the same height, h, there exist two topographic and one Rossby modes. The frequency of one of the topographic modes is ‘locked’ inside the band (−fh/2H0, fh/2H0), where f is the Coriolis parameter and H0 is the mean depth of the ocean. The frequencies of the other topographic mode and the barotropic Rossby mode are ‘locked’ above and below the band, respectively. It is also demonstrated that if the heights of cylinders are distributed within a certain range, (−h0, h0), no harmonic modes exist with frequencies inside the interval (−fh0/2H0, fh0/2H0). The topographic and Rossby modes are ‘pushed’ out of the ‘prohibited’ band.