Latent and Sensible Heat Flux at the Spray-Laden Air-Sea Interface

充满喷雾的空气-海洋界面处的潜热和显热通量

• 批准号: 1429921
• 负责人: David Richter
• 金额: $ 25.17万
• 依托单位: University of Notre Dame
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-02-15 至 2020-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1429921&HistoricalAwards=false
• 关键词: Latent; Sensible; Heat; Flux; Spray

The air-sea interface in high-wind situations, like hurricanes, is an important topic that crosses boundaries between atmospheric sciences and oceanography. Sea spray droplets are known to affect the temperature and moisture distribution in the surface layer above the ocean, which in turn can affect associated atmospheric processes. This award will provide an opportunity for a researcher and his students to work on numerical modeling of these processes using direct numerical simulation, which allows researchers to follow individual droplets as they move along in the wind. The potential impact of this project is on improved prediction of tropical cyclones, but the numerical techniques developed could potentially have an impact across a variety of scientific disciplines. The work would also contribute to the future scientific workforce through the training of a graduate student and undergraduate student.The researcher plans to address the role of sea spray on the exchanges of heat, moisture, and momentum at the air-sea interface through a suite of numerical experiments. The role of sea spray on these exchanges at high winds is uncertain due to the difficulty in making measurements in these conditions. The researcher has developed a numerical technique to track individual Lagrangian droplets through a shear-driven turbulent flow, and two-way momentum coupling was enforced for each particle allowing for a direct calculation of the bulk moment flux modifications. This project would extend that work by implementing two-way thermodynamic coupling between the droplets and the surrounding flow, allowing for a direct evaluation of spray's influence on latent and sensible heat flux and the resulting profiles of temperature and moisture. The specific research questions to be answered include: 1) Do the vertical fluxes of sensible and latent heat (and enthalpy) in an environment laden with thermodynamically-coupled droplet particles exceed those of an unladen case? 2) To what degree is the flux of salinity into the ocean enhanced by droplet evaporation, and can this lead to enhanced mixing in the ocean boundary layer? 3) Do the mean profiles of heat and humidity change immediately above the air-sea interface? 4) What concentrations of water droplets are necessary to see any effects on heat and moisture fluxes? 5) What size distribution of spray droplets can be expected when in thermodynamic equilibrium immediately above the air-sea interface?

在强风情况下的海气界面，如飓风，是一个跨越大气科学和海洋学之间界限的重要课题。 众所周知，海洋喷雾液滴会影响海洋表层的温度和湿度分布，进而影响相关的大气过程。 该奖项将为研究人员和他的学生提供一个机会，使用直接数值模拟对这些过程进行数值建模，这使得研究人员能够在风中沿着移动时跟踪单个液滴。 该项目的潜在影响是改进热带气旋的预测，但开发的数值技术可能会对各种科学学科产生影响。 这项工作还将通过培训一名研究生和一名本科生为未来的科学工作者做出贡献。研究人员计划通过一套数值实验来解决海水喷雾对海气界面热量、水分和动量交换的作用。 由于在这些条件下进行测量的困难，在大风中海水喷雾对这些交换的作用是不确定的。 研究人员开发了一种数值技术，通过剪切驱动的湍流来跟踪单个拉格朗日液滴，并对每个粒子进行双向动量耦合，从而可以直接计算体积矩通量修改。 该项目将通过实施液滴和周围流动之间的双向热力学耦合来扩展这项工作，从而可以直接评估喷雾对潜热和显热通量的影响以及由此产生的温度和湿度分布。 具体的研究问题包括：1）在一个环境中的显热和潜热（和焓）的垂直通量与热耦合液滴颗粒负载超过那些空载的情况下？2)液滴蒸发在多大程度上增加了进入海洋的盐度通量，这会导致海洋边界层混合的增强吗？3)在海-气界面上方，热、湿的平均廓线是否会立即发生变化？4)什么样的水滴浓度才能看到对热量和水分通量的影响？5)当在气-海界面上方处于热力学平衡时，可以预期喷雾液滴的尺寸分布是什么？