Understanding Whitecap Foam Decay using Shipboard Infrared Remote Sensing

这项工作的动机是需要提高参数化的分数覆盖的白浪在海洋表面上。白浪在波浪破碎过程中产生（A阶段），之后在海面上逗留（B阶段），对边界层和气候有相当大的影响。例如，它们对热量、质量和动量的交换、气溶胶的产生、海洋上层混合、气体扩散和热带风暴强度至关重要。白顶覆盖率被广泛用于估计这些和其他过程，但常规采用的风速依赖性具有数量级的不确定性，这在很大程度上是由于阶段B寿命的大变化。为了了解影响泡沫寿命的因素，将利用红外成像、气泡羽流的声学特性以及其他海洋学和气象学测量，对白浪进行船载实地研究。将对数据进行统计分析，以产生一个模型，该模型将预测各种环境中的阶段B寿命，从而更准确地估计白顶覆盖率及其推断的表面过程。白浪在卫星遥感过程中被用来估计表面风和表面风速，这两者都是气候模型中的初始变量。因此，对白浪的更可靠的了解将改进这些模型。此外，在使用卫星检索海洋颜色和初级生产估计数时，必须考虑白浪。由于这项研究，这也将更加准确。大量的人为CO2被隔离到海洋中，并通过海气界面进行交换，部分原因是通过白顶空气夹带和气泡破裂。白帽气泡破裂时产生的小液滴散射太阳辐射并充当云凝结核，影响云的反照率。了解影响当代海洋中白浪的海气界面的复杂相互作用，将使研究人员能够构建更好的白浪对气候影响的模型，并可用于预测白浪在未来地球系统中的作用。来自德克萨斯州A M大学的聋人和听力困难（HoH）学生将被招募参与这个项目。这些高影响力的学习经验将为来自其他学科的聋人和HoH学生提供参与STEM研究的机会，否则可能无法获得。预计这将导致更多的聋人和HoH学生在STEM领域获得本科学位，从而获得研究生学位和STEM职业。一名研究生将通过这项研究得到支持，并接受物理海洋学方面的培训。来自德克萨斯州A M大学校园的科学专业学生将有机会在海洋学方面获得实践研究经验，一些本科生将通过开展个人研究项目成为研究的积极合作伙伴。研究结果将主要通过同行评议的出版物和科学会议上的演讲进行传播，学生在传播过程的各个阶段都发挥着积极的作用。该项目的目标是开发一个参数模型，可以预测B期白顶的寿命。该模型将利用船上白浪红外图像的数据创建，同时测量海气界面的气象和海洋条件。将使用红外遥感，因为它提供了其他遥感技术所不能提供的清晰、明确的白顶阶段分离。这些数据将使用主成分分析进行分析，以确定每个参数对阶段B白浪寿命的相对贡献，并建立模型。红外图像将在墨西哥湾的多次巡航中记录，以捕捉各种各样的条件，为模型提供力量。船上数据将补充从现有浮标网络获取的波浪信息。这项研究是位于华盛顿，华盛顿特区的海军研究实验室（NRL）和德克萨斯A M大学海洋学系的合作。这两个机构都带来了对方没有的设备，导致合作远远大于其部分。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This work is motivated by the need to improve parameterization of the fractional coverage of whitecaps on the ocean surface. Whitecaps, which are created during wave breaking (stage A) and linger on the surface afterwards (stage B), have considerable influence on the boundary layer and climate. For example, they are critical to the exchange of heat, mass, and momentum, the production of aerosols, upper-ocean mixing, gas diffusion, and tropical storm intensity. Whitecap coverage is used expansively to estimate these and other processes, yet the routinely employed wind speed dependence has orders of magnitude uncertainty that is, in large part, due to large variations in stage B lifetime. In order to understand the factors influencing foam lifetime, a ship-based field study of whitecaps will be conducted with infrared imagery, acoustic characterization of bubble plumes and additional oceanographic and meteorological measurements. The data will be analyzed statistically to yield a model that will predict stage B lifetime in various environments leading to more accurate estimates of whitecap coverage and the surface processes they infer. Whitecaps are used during satellite remote sensing to estimate surface winds and surface albedo both of which are initializing variables in climate models. A more robust knowledge of whitecaps will therefore improve these models. Furthermore, whitecaps must be accounted for when using satellites to retrieve ocean color and primary production estimates. This will also be more accurate as a result of this research. A great deal of anthropogenic CO2 is sequestered into the ocean and exchanged across the air-sea interface, in part, through whitecap air entrainment and bubble bursting. Small droplets produced when whitecap bubbles burst scatter solar radiation and act as cloud condensation nuclei, affecting cloud albedo. Understanding the complex interactions at the air-sea interface that influence whitecaps in the contemporary ocean will enable researchers to construct better informed models of the impact whitecaps have on climate and may be used to predict the role of whitecaps in the future Earth system. Deaf and Hard of Hearing (HoH) students from Texas A&M University will be recruited to work on this project. These high impact learning experiences will provide Deaf and HoH students from other disciplines the opportunity to participate in STEM research which may otherwise not be available. It is expected that this will lead to more Deaf and HoH students earning undergraduate degrees in STEM fields leading to graduate degrees and STEM careers. A graduate student will be supported through this research and receive training in physical oceanography. Science majors from across the Texas A&M University campus will be offered an opportunity for hands-on research experience in oceanography, and several undergraduate students will become active partners in the research by conducting individual research projects. Results from the research will primarily be disseminated through peer-reviewed publications and presentations at scientific meetings, with students playing an active role at all stages in the dissemination process.The objective of this project is to develop a parametric model that can predict stage B whitecap lifetime. The model will be created using data from shipboard infrared images of whitecaps captured simultaneously with measurements of meteorological and oceanographic conditions at the air-sea interface. Infrared remote sensing will be used because it provides clear, unambiguous separation of whitecap stages not afforded by other remote sensing techniques. These data will be analyzed using a principle component analysis to determine each parameter's relative contribution to the lifetime of stage B whitecaps and to develop the model. Infrared images will be recorded in the Gulf of Mexico during multiple cruises in order to capture a wide variety of conditions that will lend strength to the model. Shipboard data will be supplemented with wave information taken from existing buoy networks. This research is a collaboration between the Naval Research Laboratory (NRL) in Washington, D.C. and the Department of Oceanography at Texas A&M University. Both institutions bring equipment that the other does not have, leading to collaboration much greater than its parts. This project may cultivate a longstanding academic-government partnership.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.