Collaborative Research: Wind turbulence over shoaling surface waves and their impact on air-sea fluxes

该项目将使用波浪跟踪大涡模拟(LES)结合风浪设施中的流动可视化工具来研究海面上空气-水界面上的动量和能量交换。总体目标是更好地了解浅水波浪对阻力系数的调制和可能的增强。这些结果将有助于发展依赖海态的海-气通量的精确参数，可纳入正在进行的大气-波浪-海洋天气和气候模式(特别是风暴潮模式)的耦合工作中。该项目包括与罗德岛大学和特拉华大学的教育和外联倡议建立联系。这些措施包括对研究生进行科学教育教育学、有效的外展战略和科学交流方面的培训；本科生研究教育暑期奖学金(REU)；学童和其他团体的实验室访问；以及开放参观。在沿海水域，观测和模拟研究表明，随着海浪减慢和变陡，海浪的浅滩阻力系数显著增加。然而，现有的模型严重低估了浅滩的波浪效应。该项目将研究风强迫如何改变浅海波浪的形状，以及波浪形状如何改变波浪上方的风(湍流)场。PI假设波浪形状和风强迫之间的耦合作用增强了浅海波浪上的阻力系数。为了验证这一点，他们将结合高分辨率的实验室观测和大涡模拟(LES)。LES的结果将与观测结果进行验证，并扩展到调查浅海海浪对标量通量的影响。这一裁决反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This project will investigate the exchange of momentum and energy across the air-water interface at the sea surface using a wave-following Large Eddy Simulation (LES) in combination with flow visualization tools in a wind-wave facility. The overall objective is to better understand modulation and possible enhancement of drag coefficient due to shoaling waves. The results will contribute to the development of accurate parameterizations of sea state dependent air-sea fluxes, which can be incorporated in the ongoing coupling efforts for atmosphere-wave-ocean weather and climate models (storm surge models in particular). The project includes linkages with education and outreach initiatives at the University of Rhode Island and University of Delaware. These include training for graduate students in science education pedagogy, effective outreach strategies, and science communication; summer fellowships in Research Education for Undergraduates (REU); Laboratory visits for schoolchildren and other groups; and open houses.In coastal waters both observational and modeling studies show that the drag coefficient is significantly enhanced by shoaling waves as waves slow down and become steeper. However, the existing models significantly underestimate the shoaling wave effect. This project will investigate how the shape of shoaling waves is modified by wind forcing and how that wave shape alters the wind (turbulence) field above the wave. The PIs hypothesize that coupled interaction between wave shape and wind forcing enhances the drag coefficient over shoaling waves. To test this, they will combine high resolution laboratory observations and large eddy simulation (LES). The LES results will be validated against observations and extended to investigate the impact of shoaling waves on scalar fluxes.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.