Quantifying Energy Dissipation From Breaking Waves Using Time-Varying Properties of Whitecap Foam

利用 Whitecap 泡沫的时变特性量化破碎波的能量耗散

• 批准号: 1434866
• 负责人: Grant Deane
• 金额: $ 70.21万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-10-01 至 2019-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1434866&HistoricalAwards=false
• 关键词: Quantifying; Energy; Dissipation; Breaking; Waves

The goal of the proposed research is to develop a remote sensing technique to quantify the energy lost by breaking waves. The work is motivated by the fundamental role that wave breaking plays in enhancing the exchange of heat, mass, momentum and energy across the air-sea interface. Furthermore, existing remote sensing techniques remain highly uncertain due to large variations in the breaking strength parameter, motivating the need to develop alternative remote sensing techniques. It is anticipated that the proposed remote sensing technique will help enhance our fundamental knowledge of wave breaking and energy dissipation, which is important for the understanding of aerosol production and gas exchange. Furthermore, the remote new sensing technique implicitly accounts for both wave scale and breaking intensity on a wave-by-wave basis, which can provide valuable information for detailed modeling of ocean waves. The impact of the study will be further broadened by the participation of undergraduate interns in the laboratory experiments to help with data collection and preliminary analysis. The project team will participate in the public outreach lecture series hosted by the Birch Aquarium.The remote sensing technique will utilize high-speed and high resolution digital images of the time-varying properties of whitecap foam during active wave breaking and will be validated against a series of well-controlled laboratory experiments using seawater and breaking wave packets. Present remote-sensing techniques rely on measuring breaking wave speed to estimate breaking wave energy dissipation, but, critically, there is a lack of consensus in the literature regarding the most appropriate way to measure breaking wave speed. This has direct implications for estimates of the breaking strength parameter, which has been reported to vary by 4 orders of magnitude. Development of a new remote sensing technique will offer a parallel approach to the present methodology. Answers to the following key questions will be sought: 1) Can high-resolution and high-speed digital photography be used to quantify energy dissipation during wave breaking on a wave-by-wave basis? 2) Can the new remote sensing technique, developed using breaking waves generated by linear wave superposition, be applied to wind-driven breaking waves? 3) Using existing datasets of sea surface images, can the new remote sensing technique be applied to breaking waves in wind-driven seas? The proposed research will involve a combination of laboratory experiments and analysis of an existing database of sea surface images to begin to estimate energy dissipation for individual breaking waves. The laboratory experiments will be based on observations of breaking waves in both the 33 meter glass wave channel and the 40 meter wind-wave channel at the Scripps Institution of Oceanography. Importantly, the use of these two wave channels will ensure breaking waves are generated across a wide range of scales and with different forcing mechanisms (wave-wave interaction and wind shear stress). Whitecap foam, bubble plume and wave energetics will be monitored for spilling through plunging breakers using a downward looking camera to monitor the surface whitecap properties, a sideward looking camera to monitor bubble plume characteristics and wave gauges to accurately characterize energy dissipation due to breaking. This comprehensive experimental approach will provide the necessary data to develop the remote sensing technique for use in future-planned field studies.

拟议的研究的目的是开发一种遥感技术来量化通过破坏波的损失的能量。这项工作是由波浪破裂在增强空气界面上的热，质量，动量和能量的交换方面的基本作用所激发的。此外，由于断裂强度参数的差异很大，现有的遥感技术仍然高度不确定，从而激发了开发替代性遥感技术的需求。预计拟议的遥感技术将有助于增强我们对波浪破裂和耗能的基本知识，这对于了解气溶胶生产和气体交换非常重要。此外，远程新的传感技术在逐波的基础上隐含地解释了波浪量表和破坏强度，这可以为海浪的详细建模提供有价值的信息。本科实习生参与实验室实验，以帮助进行数据收集和初步分析，将进一步扩大研究的影响。该项目团队将参加由桦木水族馆主持的公开外展演讲系列。遥感技术将利用活跃波浪破裂期间WhiteCap泡沫的高速和高分辨率数字图像，并将针对使用Seawater和Breaking Wave Pakeets的一系列良好的实验室实验来验证。当前的遥感技术依赖于测量断裂波速度来估计波浪能量耗散，但是，在文献中，关于测量断裂波速度的最合适方法，文献中缺乏共识。这对断裂强度参数的估计有直接的影响，据报道，该参数的变化为4个数量级。开发新的遥感技术将为当前方法提供平行的方法。将寻求以下关键问题的答案：1）高分辨率和高速数字摄影是否可以在波浪中逐步淘汰波浪中的能量耗散？ 2）使用线性波叠加产生的断裂波开发的新的遥感技术可以应用于风驱动的断裂波吗？ 3）使用现有的海面图像数据集，可以将新的遥感技术应用于风驱动的海洋中的波浪吗？拟议的研究将涉及实验室实验和对海面图像现有数据库的分析，以开始估计单个断裂波的能量耗散。实验室实验将基于在Scripps海洋学机构的33米玻璃波通道和40米的风波通道中对断裂波的观察。重要的是，使用这两个波通道将确保在广泛的尺度和不同的强迫机构（波波相互作用和风剪应力）上产生断裂波。将监测WhiteCap泡沫，气泡羽和波能量，以通过使用向下的摄像机倾斜破碎机来监视表面WhiteCap的特性，以监视侧面的摄像头，以监视泡沫羽状特性和波浪柱特性，以准确地表征因断裂而导致的能量耗散的能量。这种全面的实验方法将提供必要的数据，以开发用于未来计划的现场研究中使用的遥感技术。