Ocean Gravity-Capillary Waves: Dependence on Sea-Surface Processes and Microlayer Properties

对10厘米及更短的波，也就是所谓的“重力-毛细”波和“毛细”波的理解不足，仍然是现代波浪模型中的一个薄弱环节。要理解动量、热量和气体如何在大气和海洋之间转移，充分描述这些波及其对风强迫的反应是至关重要的。长期以来，人们一直认为海洋表面存在表面活性剂会抑制这种海浪，但在真实海洋中直接观测到这种影响的情况仍然非常罕见。降雨撞击海洋表面的物理过程也会影响表面重力-毛细管波，尽管在真实海洋中还没有观测到这种相互作用。该项目将利用最先进的观测系统分析在海上收集的未得到充分利用的数据集，描述海面的短波特性，并纳入海面微层的化学特性。这些数据将能够更好地描述重力-毛细管波及其在各种环境条件下调节的海气通量，并有助于改进现有的模型。来自数据的结果将被用于通过教育工作者地球课堂(E2C)研讨会创建刺激的教材，这是一项针对教师的专业发展计划，覆盖了拥有大量来自代表不足群体的学生的学区。研讨会的结果将通过E2C网站分享，团队成员还将向非课堂观众发表公开演讲。由于使用传统技术观察这些海浪很困难，在真实海洋中测量这些海浪的总体规模相当小。这导致对重力-毛细波对大气强迫的响应、海面化学变化以及降雨等破坏性物理过程的描述很少。将利用的新数据集包括在观测海洋表面微层(SSML)化学和生物特性的同时观测细微尺度的风浪特性。这项研究将检验三个假设，重点是短尺度的海浪，它们如何因风的强迫而增长，它们如何被表面活性剂衰减，以及它们受到降雨的影响的方式。这项工作将极大地扩展我们对短海浪特征的理解，产生丰富的重力-毛细波观测基础，这将对未来的海浪模拟工作具有不可估量的价值。将SSML的化学和生物特性纳入这一分析，将首次对重力毛细海浪对表面化学和SSML微生物组变化的尺度反应进行研究。对降雨对这些短波的影响的分析将提供对物理过程的进一步洞察，这些物理过程的机械描述在文献中都没有得到充分的描述，而越来越多地被发现对物理的海-气相互作用具有重要意义。这一奖项反映了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。

Poor understanding of ten centimeter and shorter waves, termed 'gravity-capillary' and 'capillary' waves, remains a point of weakness in modern wave models. Adequate characterization of these waves and their response to wind forcing is essential to understand how momentum, heat and gases are transferred between the atmosphere and ocean. The presence of surfactants on the ocean surface has long been understood to damp such waves, but direct observations of this effect in the real ocean remain exceedingly rare. The physical process of rain impacting the ocean surface also affects surface gravity-capillary waves, though observations of this interaction in the real ocean do not yet exist. This project is to analyze an underutilized data set collected at sea with state-of-the-art observational systems, describing short wave properties of the sea surface, and incorporating sea surface microlayer chemical properties. These data will allow a better description of gravity-capillary waves and the air-sea fluxes they mediate over a variety of environmental conditions, and help improve existing models. The results from the data will be used to create stimulating teaching materials through the Earth2Class (E2C) Workshops for Educators, a professional development program for teachers which reaches school districts with large numbers of students from underrepresented groups. Workshop results will be shared through the E2C website, and team members will also present public lectures to reach a non-classroom audience.The overall body of measurements of these waves in the real ocean is quite small, owing to the difficulty in observing them using traditional techniques. This has led to a paucity of descriptions of gravity-capillary wave response to atmospheric forcing, changes in sea surface chemistry, and disruptive physical processes such as rain. The novel dataset to be utilized included observations of fine-scale wind wave characteristics made simultaneously with measurements of sea surface microlayer (SSML) chemical and biological properties. This study will test three hypotheses focused on short-scale ocean waves, how they grow due to wind forcing, how they are attenuated by surfactants, and the ways in which they are impacted by rain. This work will greatly expand our understanding of short ocean waves characteristics, producing a rich base of gravity-capillary wave observations which will be invaluable to future wave modeling efforts. Incorporation of the SSML chemical and biological properties into this analysis will produce a first-of-its-kind study of the scale-dependent response of gravity-capillary ocean waves to changes in surface chemistry and the SSML microbiome. Analyses of the impact of rain on these short waves will provide further insight into physical processes whose mechanistic descriptions are both underrepresented in the literature and increasingly found to be of importance to physical air-sea interaction.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.