An experimental study of the structure of the air-flow above ocean surface waves

海面波浪上方气流结构的实验研究

基本信息

批准号：
1634051
负责人：
Fabrice Veron
金额：
$ 21.54万
依托单位：
University of Delaware
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2016
资助国家：
美国
起止时间：
2016-09-01 至 2020-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1634051&HistoricalAwards=false
关键词：
experimental study structure air flow

项目摘要

In recent years, considerable progress has been made in quantifying the exchange of momentum between the atmosphere and the ocean. The role of surface waves on the air-sea momentum flux is well established but our physical understanding of the airflow dynamics remains incomplete. This impedes our ability to develop improved physically based parameterizations for better weather and sea state predictions, especially in high winds and extreme conditions. In this project, the team proposes the further analysis of an existing dataset consisting of extensive high resolution 2D velocity measurements taken in the laboratory in the near surface airflow above short surface waves. It is anticipated that this work will lead to an improved understanding of the detailed, small scale physics at the air-sea interface that is necessary to build accurate coupled (ocean-atmosphere and ocean-wave-atmosphere) models of weather and climate. Furthermore, data products from this study will likely prove useful for comparison with current and future Large Eddy Simulation (LES) and Direct Numerical Simulation (DNS). This project will support the Ph.D. work of a graduate student.The importance of the surface wave in the dynamics of the coupled atmospheric and oceanic boundary layers is well recognized. In contrast, the atmospheric counterpart of this phenomenon, that is the coupling of the near surface atmospheric turbulence generated by airflow separation with the surface waves, has received less attention. To date, our incomplete understanding of the coupling between the near surface turbulence (wave or shear generated) and the surface waves remains a roadblock to the development of improved air-sea momentum flux parameterizations. Turbulence in the near surface atmospheric boundary layer is in part generated by breaking-induced airflow separation, the team thus will focus in particular on the coherence and coupling between the turbulent kinetic energy (TKE) and the surface waves. The data proposed to use covers wave ages Cp/u&#8727; varying from 1.4 (very young waves) to 66.7 (old waves) thus encompassing a large range of field-relevant conditions. The team proposes to extract turbulent and wave-coherent velocity fields by means of a triple velocity decomposition made possible by a wave- and phase-locked coordinate system. The team will then evaluate the turbulent kinetic balance and they will especially focus on the interaction between phase coherent turbulence and the surface waves.

近年来，在量化大气与海洋之间的动量交换方面取得了长足的进步。表面波在空气动量通量中的作用已经很好地确定，但是我们对气流动力学的物理理解仍然不完整。这阻碍了我们开发基于物理的参数化改进的能力，以获得更好的天气和海平面预测，尤其是在大风和极端条件下。在这个项目中，团队提出了对现有数据集的进一步分析，该数据集包括大量高分辨率的2D速度测量，在实验室中在短表面波上方的近表面气流中进行的。预计这项工作将导致对空气接口处详细的小规模物理学的了解，这是建立天气和气候模型的准确耦合（海洋 - 大气和海浪 - 大气）模型所必需的。此外，这项研究的数据产品可能会证明可用于与当前和未来的大型涡流模拟（LES）和直接数值模拟（DNS）进行比较。该项目将支持博士学位。研究生的工作。表面波在耦合大气和海洋边界层的动力学中的重要性已得到充分认识。相比之下，这种现象的大气对应物，即气流分离与表面波产生的近表面大气湍流的耦合，受到了较少的关注。迄今为止，我们对近表面湍流（产生的波或剪切）和表面波之间的耦合的不完全理解仍然是改善空气动量通量参数化的发展。近表面大气边界层中的湍流部分是由于破裂引起的气流分离而产生的，因此团队将特别集中在湍流动能（TKE）和表面波之间的相干性和耦合上。提议使用的数据覆盖波年龄CP/U＆＃8727;从1.4（非常年轻的波）到66.7（旧波）不等，因此涵盖了相关的范围相关条件。该团队建议通过通过波和相锁的坐标系实现的三个速度分解来提取湍流和波连通速度场。然后，团队将评估湍流的动力学平衡，它们将特别关注相干湍流与表面波之间的相互作用。