南海陆坡复杂地形对内波关键动力过程的影响

地形是影响内波生成传播的关键因子之一，南海陆坡有着丰富的内波现象，同时陆坡处地形结构复杂，有着斜坡、峡谷群等典型的地形地貌特征，因此南海陆坡是研究内波地形效应天然的实验场所。东沙斜坡、神狐峡谷群等是典型的南海陆坡地形，需要超高分辨率的地形数据才可以解析。本项目通过布设已购置的低成本、高效率的倒置式回声仪阵列，配合走航断面调查等观测手段，结合理论分析模型和超高分辨率海洋内波模式，引入超高分辨率多波束地形数据，阐明陆坡地形效应引起的内潮、内孤立波三维反射和折射规律，研究陆坡复杂地形控制下内波引起不稳定机制及其引起的混合和耗散，阐明地形关键参数在上述过程中的敏感性和作用效果。通过本项目的研究，有望深入理解高分辨率地形作用下内波生成、传播和反射等关键物理过程，建立联系深远海和大陆架的桥梁，为海洋生态、地质等研究提供科学支持，服务于海洋科学研究和经济国防建设。

Topography is one of the key factors affecting the generation and propagation of internal waves. Internal waves are frequently observed near the shelf of the South China Sea. The shelf topography is also complex including slopes, canyons, etc. Therefore, the South China Sea shelf is a natural region to study internal waves. In this project, an inverted echo sounder array will be implemented, in coordinate with cross-section surveys, in order to monitor the internal waves. Super-high-resolution topography data were acquired from a multibeam survey. Based on in situ data, analytical and numerical models, we propose to elucidate the topographic effects of the shelf break on the internal wave reflection and refraction, and the role of incident internal waves on the local internal wave generation. Instabilities and corresponding mixing caused by the internal waves will be specially examined. Key topographic parameters of the shelf break, which determine the internal wave behaviors, will be summarized. Through this project, we expect to further understand the key processes during the interaction between internal waves and topography. This study will establish a connection between deep sea and continental shelf, providing support for oceanographic studies including marine ecological and geological studies, as well as serving for national economy and surveillance.