MOMS: a Minimal Ocean Mixing System

MOMS：最小的海洋混合系统

• 批准号: 2049213
• 负责人: Alberto Scotti
• 金额: $ 51.35万
• 依托单位: University of North Carolina at Chapel Hill
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-15 至 2024-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2049213&HistoricalAwards=false
• 关键词: MOMS; Minimal; Ocean; Mixing; System

Despite occurring on centimeter and smaller scales, turbulent stratified mixing in the ocean affects the circulation at basin scales. Much work has been devoted to understanding how to express the efficiency of the process in terms of local turbulent parameters. Recent work though suggests that the physics of stratified mixing cannot be abstracted from the larger context in which it occurs. In this project, laboratory experiments will be conducted in a tank large enough, and suitably forced, that it may approximate more faithfully the conditions observed in the ocean, a Minimal Ocean Mixing System (MOMS). The laboratory measurements will provide a way to test theoretical and practical ways to represent mixing in computer models. Stratified turbulent mixing in a similar environment is also present in the atmosphere, and this research will therefore have a spill-over effect in atmospheric sciences. The present measurements and numerical simulations will also constitute a new dataset which can be used as a training set for Artificial Intelligence algorithms reduced order models and data-assimilation techniques which require a substantial knowledge of the flow for their validation. Finally, reducing uncertainties of irreversible mixing using the present research will improve the predictive power of general circulation models at climate scales. The PI will make every effort to advertise the postdoc position broadly so to reach candidates that traditionally have been marginalized. The PI will also work with the local chapter of SCIREN, an organization that connects STEM researchers with local teachers to improve the quality and scientific literacy of youths.It is clear that the recent work surveyed shows a shift in the focus from a purely local characterization of stratified mixing (e.g., the quest for parameterizations of mixing efficiency based on the buoyancy Reynolds number) to a view that sees mixing as the end product of a dynamic that starts at much larger scales and is (potentially) much more intertwined than previously recognized. Experimentally, this requires rethinking the problem of stratified mixing to include a more natural way to force the problem, and a domain sufficiently large to accommodate both the anisotropic and the isotropic part of the spectrum, a MOMS. The dataset collected in these experiments and numerical simulations will therefore, constitute a novel way to test and validate theoretical arguments to model the energy exchanges in stratified turbulent flows across the anisotropic / isotropic divide. In addition, this research aims to provide a link between vertically/horizontally towed instruments and planar / volume-resolved measurements. This project also intends to establish a link between near-ocean conditions combining theoretical with technical challenges at unprecedented scales for which the UNC Joint Fluids lab is designed. In addition, the Craya-Herring framework combined with the structure functions methods will provide the state-of-the-art theoretical foundations to analyze the role of the turbulence where intermittency remains a key open question to analyze and interpret field measurements, since mixing events are rarely observed nor statically converged in field measurements of strongly stratified turbulence.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.

尽管发生在厘米和较小的尺度上，但海洋中的湍流分层混合会影响盆地尺度的循环。已经致力于了解如何以局部湍流参数来表达过程的效率。尽管最近的工作表明，分层混合的物理学不能从发生的较大背景中提取。在这个项目中，将在足够大的储罐中进行实验室实验，并适当强迫，以至于它可以更忠实地近似于在海洋中观察到的条件，这是一种最小的海洋混合系统（MOMS）。实验室测量将提供一种测试理论和实用方法来表示计算机模型中混合的方法。在大气中也存在类似环境中的分层湍流混合，因此这项研究将对大气科学产生溢出作用。目前的测量和数值模拟还将构成一个新的数据集，可以用作人工智能算法的培训集，减少了订单模型和数据辅助技术，该技术需要对验证的流量有丰富的了解。最后，使用本研究减少不可逆混合的不确定性将提高气候尺度上一般循环模型的预测能力。 PI将尽一切努力广泛地宣传博士后职位，以吸引传统上被边缘化的候选人。 The PI will also work with the local chapter of SCIREN, an organization that connects STEM researchers with local teachers to improve the quality and scientific literacy of youths.It is clear that the recent work surveyed shows a shift in the focus from a purely local characterization of stratified mixing (e.g., the quest for parameterizations of mixing efficiency based on the buoyancy Reynolds number) to a view that sees mixing as the end product of a dynamic that starts at much larger比例比以前认识到的（潜在的）相互交织要多得多。在实验上，这需要重新考虑分层混合的问题，以包括一种更自然的方法来强制该问题，并且一个足够大的域以适应各向异性和各向同性部分的谱系，即妈妈。因此，在这些实验和数值模拟中收集的数据集将构成一种新的测试和验证理论参数的新方法，以模拟各向异性 /各向同性鸿沟的分层湍流中的能量交换。此外，这项研究旨在提供垂直 /水平牵引仪器与平面 /体积分辨测量的联系。该项目还打算在近乎海洋的条件之间建立联系，该条件将理论挑战与前所未有的尺度相结合的技术挑战之间设计了联系。此外，克雷亚式的框架与结构函数方法相结合，将为最先进的理论基础分析分析湍流的作用，在该湍流中，间歇性仍然是分析和解释现场测量的关键问题，因为混合事件的混合事件在很大程度上被观察到了很大的观察到的，在不静态地融合了强烈分层的范围内，该措施均可表现出较强的范围。使用基金会的智力优点和更广泛的影响评估标准进行评估。