摘要
为了更好地了解内孤立波的特性,分别利用椭圆余弦波方法和摄动展开方法,对两层模型下内孤立波K-dv方程的频散关系进行了推导。结果显示:利用后一种方法得到的两层模式下内孤立波K-dv方程的频散关系是一种方便、实用的解析式。据此解析式可进一步得到内孤立波半波宽度与内波波数间的关系,从而可将内孤立波理论与内波合成孔径雷达(SAR)图像联系起来。用此解析式计算得到的内孤立波频率和相速度与实测结果具有很好的一致性,因而为进一步进行分析和利用数据估计内孤立波的部分参数提供了理论依据。对解析式中频散项和非线性项量级的进一步分析认为,非线性项的作用在从SAR图像中提取内波振幅等参数时最好不予忽略。
To understand the internal solitary waves better, a dispersive relation of internal solitary wave is deduced from a two-layer model of K-dv equation by elliptical cosine function and by perturbation expansion individually. The dispersive relation from the second method is an analytic equation, which is convenient for application. A simple relation between half wave width and wave number of internal solitary waves, gained from the dispersive relation, builds a bridge between theory of internal solitary wave and Synthetical Aperture Radar（SAR） images of internal solitary waves. The frequency and phase velocity calculated by the dispersive relation agree well with field observations and this shows that the relation can be used to estimate parts of the internal solitary waves＇ parameters. It is indicated from the comparison between the dispersive and the nonlinear term in the analytic equation that it is better to keep the nonlinear term when extracting the parameters of internal solitary waves from SAR images.
出处
《水动力学研究与进展（A辑）》
CSCD
北大核心
2005年第5期673-679,共7页
Chinese Journal of Hydrodynamics
基金
山东省自然科学基金资助(Y2000E04)
微波成像技术国家重点实验室基金资助项目(51442020303JW1002)
