Lagrangian observations of turbulence in breaking surface waves

破碎表面波中湍流的拉格朗日观测

• 批准号: 1061732
• 负责人: Miguel Canals
• 金额: $ 22.7万
• 依托单位: University of Puerto Rico Mayaguez
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-15 至 2015-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1061732&HistoricalAwards=false
• 关键词: Lagrangian; observations; turbulence; breaking; surface

Understanding the dynamics of breaking waves is one of the most difficult fundamental problems in the ocean sciences. Wave breaking produces turbulent flows populated by intense short-lived 3D vortex structures, air cavities and aerated regions. The structure and dynamics of these vortices and cavities have never been fully examined in the field due to the difficulty of sampling the flow in a synoptic way. The PI requests funding to develop Lagrangian drifters to examine the temporal evolution of individual waves as they break using drifters equipped with miniature accelerometers and gyroscopes, GPS units, video camera and pressure sensors, to reconstruct the 3D distribution of turbulence, dissipation, bubble entrainment and pressure in spilling and plunging gravity waves. These drifters will act as inertial particles which will be entrained in the breaking region. The drifter movements will be used as a proxy for the velocity and turbulence structure of the breaker, and spectral analysis will be employed to relate the high-frequency data with the large-scale decay of individual waves. Broader Impacts: The proposed instrumentation has the potential to impact our understanding of the wave breaking process and provide needed observational constraints on model outputs. It would be difficult to overstate the importance of these impacts: wave breaking plays an important role in air-sea exchange processes and a fundamental role in the production of marine aerosols. Training of minority graduate and undergraduate students in an area (Puerto Rico, Caribbean) where such opportunities are relatively scarce. The proposed work will help establish a coastal research effort at the University of Puerto Rico Mayaguez. It will entrain students in Puerto Rico into study of the coastal environment, most of whom will be Hispanic.

破碎波动力学是海洋科学中最困难的基本问题之一。波浪破碎产生湍流，湍流由强烈的短暂的3D涡流结构、空气空腔和掺气区域组成。这些涡和空腔的结构和动力学从来没有在现场进行过充分的研究，因为很难以天气学的方式对气流进行采样。PI要求提供资金开发拉格朗日漂移器，以检查单个波浪的时间演变，因为它们使用配备微型加速度计和陀螺仪，GPS单元，摄像机和压力传感器的漂移器，以重建溢出和暴跌重力波中湍流，耗散，气泡夹带和压力的3D分布。这些漂移物将作为惯性颗粒，其将被夹带在破碎区域中。漂流物的运动将被用作破碎机的速度和湍流结构的代理，频谱分析将被用来将高频数据与单个波的大规模衰减联系起来。更广泛的影响： 拟议的仪器有可能影响我们的波破碎过程的理解，并提供所需的观测模型输出的限制。很难夸大这些影响的重要性：波浪破碎在海气交换过程中发挥重要作用，在海洋气溶胶的产生中发挥根本作用。在机会相对较少的地区（波多黎各、加勒比）培训少数民族研究生和本科生。拟议的工作将有助于在波多黎各马亚圭斯大学建立一个沿海研究工作。它将引导波多黎各的学生研究沿海环境，其中大部分将是西班牙裔。