Breaking characteristics of large amplitude internal solitary waves

内孤立波（ISWs）是地球大气和海洋中普遍存在的特征。特别是在沿海海域、峡湾、湖泊和大气边界层的分层流动中，它们是一种常见的特征。它们是沿密度界面在稳定分层流体中传播的永久形式的有限振幅波。在海洋中，它们是由海底山脊或大陆架上的潮汐流产生的，或者是由沿着复杂的海岸地形被风困住的轻水团或重水团松弛时产生的。通常，这些波是高度非线性的，可能达到非常大的振幅。断裂的isw在其传播的环境中会导致显著的垂直混合。它们是混合、湍流、质量和动量传递的重要来源。在物理海洋学中，争论的最热门问题之一是isw在沿海海洋整体混合中的作用——这一过程反过来又对全球海洋环流、热输送和气候模拟产生影响。在近海石油勘探、生产和海底储存活动正在进行的沿海和海洋地区，破碎和非破碎isw都对此类设施的安装和操作造成重大危害。此外，由内波引起的混合重新分配了营养物质和溶解气体，从而影响了海洋中的生物生产力。为了理解isw在这些情况下的行为，必须更好地理解导致断裂和随后产生的湍流的进化过程。本文将研究isw的稳定性和后续的波致流动。提出了一种理论与实验相结合的参数化建模方法。

Internal solitary waves (ISWs) are ubiquitous features in the Earth's atmosphere and ocean. In particular, they are a commonly occurring feature in the stratified flows of coastal seas, fjords, lakes and the atmospheric boundary layer. They are finite-amplitude waves of permanent form that propagate along density interfaces in stably-stratified fluids. In the ocean they are generated by tidal flows across sub-sea ridges or continental shelves, or when pools of light or heavy water masses relax, having been trapped by the wind along complex coastal topographies. Typically, the waves are highly nonlinear and may attain very large amplitudes. Breaking ISWs can result in significant vertical mixing in the environment in which they propagate. They are an important source of mixing, turbulence and mass and momentum transfer. In physical oceanography, one of the most topical issues of debate is the role of ISWs on the overall mixing of coastal oceans - a process that, in turn, has implications for global ocean circulation, heat transport and climate modelling. In coastal and oceanic regions where offshore petroleum exploration, production and sub-sea storage activities are in progress, both breaking and non-breaking ISWs present significant hazards to the installation and operation of such facilities. In addition, mixing induced by internal waves redistributes nutrients and dissolved gases, thus affecting biological productivity in the oceans. To understand the behaviour of ISWs in these contexts, it is imperative that the evolutionary processes that lead to breaking and the subsequent generation of turbulence are better understood. This proposal will investigate the stability and subsequent wave induced flow of ISWs. A combined theoretical and laboratory parametric modelling study is proposed.