Wave Energy Dissipation and the Distribution of Breaking Crests

本研究的目的是同时测量大型湖泊波浪破碎波峰长度和能量耗散的速度分布。这些数据将用于检验Phillips[1985]关于周转率和能量耗散的公式，并确定被动和主动红外技术在多大程度上可以提供由波浪破碎引起的能量耗散的远程测量。重点将是充分表征小尺度和微尺度的破波，利用红外成像的独特能力来量化微破波的发生和在所有尺度上被破波破坏的表面面积。将进行现场实验，同时测量破碎波峰长度的分布、表面周转率和能量耗散率。该实验将在华盛顿湖进行，以提供相对简单的波场并收集所需的数据量。破碎波的尺度分布对于量化与波浪模型相关的耗散、提高我们对混合层过程的理解以及对船舶和海洋结构的安全都很重要。Phillips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，为量化波浪破碎提供了一个框架，并可能仅从运动学和几何测量中推断出破碎动力学。虽然最近有许多关于破碎波峰长度分布的测量，但没有一个是与耗散测量相结合的。此外，以往用于测量破碎波峰长度分布的技术无法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破碎波峰长度分布和从白浪鳞到微断路器的能量耗散率的需要。该项目将通过一名研究生参与工作的各个方面以及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资助暑期本科生研究计划（SURP）参加，通过该计划，首席研究员过去曾指导过学生。将努力招收来自弱势群体的学生，这是该计划所强调的。研究基础设施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。对社会的好处包括有助于我们对自然环境的理解，从而更好地参数化与波浪建模、混合层过程以及船舶和海洋结构的安全性相关的波浪破碎。

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.