热分层水槽中波浪混合的实验研究

Currently wave-induced mixing is one of most concerned issues in the world-wide community of physical oceanography. The present project is aiming at carring out a laboratory experiment on mixing due to deep water wave, in a thermo-stratified wind wave tank. In the experiment, wind speed, wave elevation,water temperature and velocity beneath the water surface are measured systematically. The mixing processes due to wind waves, swell and mixed waves with various thermocline will be investigated, in order to reveal the mechanism of wave mixing. Data analysis is based on theoretical ground and the similarity will be applied to scale the parameterization of wave mixing, which is expected to be applicable to the realistic ocean. Finally, the ocean circulation model would strengthen its ability to simulate the mixing layer by inclusion of the proposed parameterization.

海浪在上层海洋中的混合作用是目前国际上物理海洋的热点研究问题。本项目拟在实验室热分层风浪槽内系统地进行深水波浪混合的观测，同步观测风、浪、水温、流速，研究不同类型温跃层情形下风浪、涌浪、混合浪的混合过程，揭示它们的混合机制，在理论的指导下分析观测数据，基于相似律试图建立可适用于外海的波浪混合参数化方案，为提高海洋环流模式模拟混合层的能力提供所需的有物理依据的参数化方案。

海浪在上层海洋中的混合作用是目前国际上物理海洋的热点研究问题，本项目利用大型热分层风浪槽系统地研究了风浪、涌浪和混合浪情形下的浪致混合过程，研究了浪致混合效应随深度的变化情况。同时项目还开展了与波浪破碎及海气交换有关的研究工作。阐明了波浪的混合机制、波浪混合影响深度的尺度；揭示了浪致混合效应对于浪况的随机性有显著的依赖性，波浪混合的影响深度既依赖于波高也依赖于波长；根据迄今各种外海和室内观测得到的高风速下拖曳系数随风速的变化，一致性地反演出占主导地位沫滴的粒径大小。这些成果对于理解上层海洋与底层大气间的海气交换过程与机制具有重要科学意义，有望在海气耦合模式中得到应用。