Wave Energy Dissipation and the Distribution of Breaking Crests

本研究的目的是同时测量大型湖泊中波浪破碎的波峰长度和能量耗散的速度分布。这些数据将被用来测试Phillips[1985]公式的周转率和能量耗散，并确定被动和主动红外线技术能够在多大程度上提供由于波浪破碎而产生的能量耗散的远程测量。重点将放在充分描述小尺度和微尺度波破裂的特征上，利用红外成像的独特能力，在所有尺度上量化微破裂的发生和被波破裂破坏的表面积。现场实验将同时测量破碎波峰长度的分布、表面周转率和能量耗散率。实验将在华盛顿湖上进行，以提供一个相对简单的波浪场并收集所需的数据量。智能优点破碎波的尺度分布对于量化与波浪模型相关的耗散、增进我们对混合层过程的理解以及对船舶和海洋结构物的安全具有重要意义。菲利普斯的公式将破碎引起的能量耗散与破碎波峰长度的分布作为波峰速度的函数联系起来，提供了一个框架，可以用来量化波浪破碎，并可能仅从运动学和几何测量来推断破碎动力学。虽然最近已经有一些关于破碎峰长度分布的测量，但没有一项是与耗散测量相结合进行的。此外，以往用于测量破碎波峰长度分布的技术不能覆盖小尺度和微尺度的破碎波。拟议的活动将解决同时测量从白浪到微破碎机鳞片的破碎波峰长度分布和能量耗散率的需要。更广泛的影响该项目将通过一名研究生参与所有方面的工作和两名本科生参与暑期实验来促进教学、培训和学习。本科生将通过华盛顿太空助学金暑期本科生研究项目(SURP)参与，首席研究员过去曾通过该项目指导学生。将努力从代表性不足的群体中招收学生，这是该计划强调的。将通过建造可重复使用的近地表测量水下塔和开发新的红外测量能力来加强研究基础设施。对社会的好处包括对我们对自然环境的理解的贡献，这将导致与波浪建模、混合层过程以及船舶和海洋结构物的安全相关的波浪破碎的更好的参数化。

The objectives of this study are to simultaneously measure the speed-distribution of breaking crest lengths and energy dissipation due to wave breaking in a large lake. The data will be used to test Phillips [1985] formulation for the turnover rate and energy dissipation and determine the extent to which passive and active infrared techniques can provide a remote measurement of energy dissipation due to wave breaking. Emphasis will be on adequately characterizing small-scale and microscale wave breaking usingthe unique capabilities of infrared imaging to quantify the occurrence of microbreaking and the surface area disrupted by wave breaking at all scales. Field experiments will be conducted to simultaneously measure the distribution of breaking wave crest lengths, the surface turnover rate, and the energy dissipation rate. The experiment will be conducted on Lake Washington to provide a relatively simple wave field and to gather the required amount of data.Intellectual Merit The scale distribution of breaking waves is important for quantifying dissipation relevant to wave models, for improving our understanding of mixed layer processes, and for the safety of ships and marine structures. Phillips' formulation relating energy dissipation due to breaking to the distribution of breaking crest lengths as a function of crest speed, provides a framework with which to quantify wave breaking and potentially infer breaking dynamics from kinematic and geometric measurements alone. Although there have been a number of recent measurements of the distribution of breaking crest lengths, none have been made in conjunction with dissipation measurements. Furthermore, the previous techniques used to measure the distribution of breaking crest lengths are not able to cover small-scale and microscale breaking waves. The proposed activity will address the need for simultaneous measurements of the distribution of breaking crest lengths and the energy dissipation rate from scales of whitecaps to microbreakers. Broader Impacts The project will promote teaching, training, and learning through participation of a graduate student in all aspects of the work and the participation of two undergraduates in the summer experiments. The undergraduates will participate via the Washington Space Grant Summer Undergraduate Research Program (SURP), through which the principal investigator has mentored students in the past. Efforts will be made to recruit students from an underrepresented group, which the program emphasizes. The infrastructure for research will be enhanced by building a reusable underwater tower for near-surface measurements and developing new infrared measurement capabilities. The benefits to society consists of a contribution to our understanding of the natural environment that will lead to better parameterizations of wave breaking relevant to wave modeling, mixed-layer processes, and the safety of ships and marine structures.