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题名	浅海非线性内波研究
作者	王涛
学位类别	博士
答辩日期	1999
授予单位	中国科学院声学研究所
授予地点	中国科学院声学研究所
关键词	浅海内波 非线性 双谱 模型
中文摘要	内波对整个海洋能量平衡和近海工程作业有重要影响，并是浅海波导中声场起伏的决定性因素。因此，浅海内波是当前国际前沿课题之一。本文对陆架内潮、内孤立波、内涌潮和内孤立涌潮的遥感和实地观测结果，内波场模型，浅海内波与声场的相互作用等进行了评述。给出了在我国近海开展的数次水声实验中获得的内波数据，特别是黄海内波数据。数据表明，季节性温跃层中有长周期、大振幅内波活动。这种内波波形不对称，具有非线性，并对频谱有很大影响。获得了黄海内波的二阶、三阶和四阶矩及统计分布。方差表明内波受一号简正波控制。非零的偏度值反映内波波面的垂向不对称和非正态分布，偏度系数可能大于1。峰度系数通常大于3。统计分布一般正偏，并有比相应正态分布高的峰。分析了浅海内波的双谱，发现功率谱峰之间及谱峰与前三次谐波间有强二次相互作用。双谱的实部和虚部分别代表每一频率偶对波面垂直和水平不对称性（偏度和不对称度）的贡献。非零的不对称值反映了锯齿状的波形。基于观测结果和上述分析，建立了一个浅海内波模型。由KdV方程，导出了内波的椭圆余弦波解。提出内波位移场由两部分组成：由主导地位、具有确定性的椭圆余弦波部分和随机的线性波部分。本模型预报结果与实验数据相符合。
英文摘要	Internal waves can significantly influence energy transport within the ocean and offshore engineering operation, and are the main cause of sound fluctuations in a shallow water waveguide. Therefore, the study of shallow-water internal waves is a subject of great present interest. The remote sensing and in situ observations of shelf internal tides, solitary waves, bores and solibores, spectral models of the internal wave field, and shallow-water internal wave/acoustic field interaction are reviewed. The internal wave data obtained during the experiments in the offshore areas of the China seas, especially the Yellow Sea data, are presented. It is shown that large amplitude, long internal waves occur in the seasonal thermoclines. The internal waves have asymmetric waveforms, and so they are nonlinear. The spectral effects of these nonlinear internal waves are significant. The second, third and fourth moments and statistical distributions of the internal waves are obtained. The variances indicate that the internal waves are dominated by the first mode. The non-zero skewness coefficients, which may exceed unity, statistically measure the vertical asymmetry and the non-Gaussian distribution of the internal wave elevations. In general, the kurtosis coefficients are greater than 3. The probability distributions are positively skewed and have higher peaks than the normal generally. Bispectra of the internal waves are analyzed. It is found that strong quadratic interactions occur within the power spectral peak, and also between the peak and its first three harmonics. The real and imaginary parts of the bispectra represent the contributions to the vertical and horizontal asymmetry (skew-ness and asymmetry) of the elevations from each frequency pair respectively. The non-zero asymmetry values indicate the sawtooth-like waveforms. Based on the observations and the above analyses, a model for the shallow-water internal waves is developed. The cnoidal internal wave solution is derived from the KdV equation, and the internal wave displacement field is represented as a process composed of two components: a dominant, deterministic back-ground component due to cnoidal internal wave groups and a stochastic linear wave component. Comparison of the model with the data shows reasonable agreement.
语种	中文
公开日期	2011-05-07
页码	87
内容类型	学位论文
源URL	[http://159.226.59.140/handle/311008/600]
专题	声学研究所_声学所博硕士学位论文_1981-2009博硕士学位论文
推荐引用方式 GB/T 7714	王涛. 浅海非线性内波研究[D]. 中国科学院声学研究所. 中国科学院声学研究所. 1999.

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