到目前为止对内波的观测研究主要是定点锚定等时间序列研究或者卫星遥感图片的瞬时快照研究等，缺乏对特定非线性内波以及其时空的演化与相互作用的实时跟踪和定量测量。本项目旨在结合无人机机载航拍、现场走航观测、以及实验室PIV粒子和合成纹影实验，对南中国海西北部大振幅近表面非线性内波的传播演化及波-波相互作用等三维时空演化过程进行实时定量的测量，在实验室中对非线性内波的传播演化和相互作用过程进行模拟和定量测量，并在经典模式的基础上建立能够描述所观测的传播演化和相互作用的模式，加强其物理机制的深入研究和理解，具体主要包括：近表面大振幅非线性内波在变化的背景场中的传播演化以及极性转换，重点测量和研究非线性内波的各波要素随时间空间的变化；非线性内波的波-波相互作用的特性及演化，侧重研究倾斜波-波相互作用，重点测量和研究相互作用前后及相互作用过程中内波的波要素特性以及其时空演化。

Until now, most of the observational work on nonlinear internal waves uses methods such as fixed mooring time serial observations or satellite remote sensing snapshots etc, lacking real-time tracking measurements of the propagation and evolution of certain internal waves or wave-wave interaction patterns. This proposed project aims to combine photo imaging onboard UAV (Unmanned Aerial Vehicle), onsite water column measurements, laboratory PIV and synthetic schlieren experiments to quantitatively study the large amplitude near-surface nonlinear internal waves' propagation, evolution, and wave-wave interactions in the northwestern South China Sea. The proposed work mainly includes: the propagation and evolution processes of nonlinear internal waves propagating and evolving in the varied background stratification including polarity conversion, focusing on measuring and studying wave properties and their temporal and spatial evolution; the evolution processes of wave-wave interactions of nonlinear internal waves, especially oblique interactions, focusing on measuring and studying wave properties before, during, and after the interaction and their temporal and spatial evolution.