内孤立波激发海面浪潮的机理与演化研究

An internal solitary wave can excite a fully localized ‘rip’ region on the sea surface, which is called the ‘surface signature’ or ‘tide rip’ in the literature. The existence of the tide rip results in a significant change in reflectance as seen in satellite images, which provides a method for parameter inversion of internal solitary waves, therefore is of great importance in both science and engineering. In the proposed project, large-amplitude internal solitary waves and the associated tide rips are studied numerically and experimentally in a two-fluid system bounded above by a free surface. This is a multi-layer, multi-scale and strongly nonlinear problem, and the free boundary nature adds complexity, therefore it is not easily amenable to analysis. Based on the combination of multi-scale modeling, laboratory experiments, and high-resolution numerical simulations for the primitive Euler equations, we aim at understanding the resonant coupling between internal solitons and free-surface modes, as well as the generation mechanism of rips and their tempo-spatial distributions. Furthermore, via analyzing the hydrodynamic parameters of the ocean, internal solitons and the associated rips, we aim to establish the quantitative relationship among these three. The application of the theoretical and numerical results to the South China Sea will be carried out at last. This project is expected to contribute to the parameter retrieval of ocean internal solitary waves.

内孤立波能够在海洋表面激发出完全局部化的浪潮区，被称为激潮现象。激潮的存在使得卫星遥感图片所反映的海洋表面反射特征发生明显的变化，为内孤立波的参数反演提供了途径，具有重要的科学意义和应用价值。本项目以大振幅的内孤立波及其所激发的海洋表面特征波群为研究对象，以带自由面的两层流体系统为数学模型，综合运用多尺度建模、完全非线性欧拉方程的高精度数值模拟、实验室机理性实验这三种手段对激潮现象这一多界面、多尺度、强非线性的自由边界问题进行深入研究。分析内波与海洋表面波的耦合演化机制，揭示内波激潮的形成机理，得到潮区的时空分布规律。联合分析海洋参数、内孤立波的水动力学参数，及其所激发的海面波浪的水动力学参数这三者之间的关系和变化规律，最终定量地建立它们在力学表征上的关联，并对南海内波开展初步的应用，为提升内孤立波反演技术的精度和水平提供理论基础和分析方法。

内孤立波能够在海洋表面激发出完全局部化的浪潮区，被称为激潮现象。激潮的存在使得卫星遥感图片所反映的海洋表面反射特征发生明显的变化，为内孤立波的参数反演提供了途径，具有重要的科学意义和应用价值。本项目以大振幅的内孤立波及其所激发的海洋表面特征波群为研究对象，以带自由面的两层流体系统为数学模型，综合运用多尺度建模、完全非线性欧拉方程的高精度数值模拟、实验室机理性实验这三种手段对激潮现象这一多界面、多尺度、强非线性的自由边界问题进行深入研究。分析内波与海洋表面波的耦合演化机制，揭示内波激潮的形成机理，得到潮区的时空分布规律。联合分析海洋参数、内孤立波的水动力学参数，及其所激发的海面波浪的水动力学参数这三者之间的关系和变化规律，最终定量地建立它们在力学表征上的关联，并对南海内波开展初步的应用，为提升内孤立波反演技术的精度和水平提供理论基础和分析方法。