Collaborative Research: Probing internal gravity wave dynamics and dissipation using global observations and numerical simulations

合作研究：利用全球观测和数值模拟探测内部重力波动力学和耗散

• 批准号: 2319142
• 负责人: Brian Arbic
• 金额: $ 83.46万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2026-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2319142&HistoricalAwards=false
• 关键词: Collaborative; Research; Probing; internal; gravity

This project will map the space-time geography of internal gravity wave (IW) dissipation and mixing, and the underlying dynamics, using state-of-the-art high-resolution global and regional IW models along with theory and observations of IWs. The research will employ global models, regional models, observations, and theory to take a first step towards a future in which IW dissipation and mixing arise naturally in models, without being parameterized. The project will support two summer schools on ocean and environmental science in Kenya, East Africa, to complement the successful West African summer schools that has been run every year since 2015, with cumulative participation of several hundred African participants and several dozen US participants.The Principal Investigators hypothesize that the representation of the IW spectrum in global IW models is sufficiently realistic for the models to make useful predictions about spatial and temporal distributions of IW dissipation and, by extension, IW-induced mixing. They also hypothesize that much as an inertial subrange is implicitly resolved by Large Eddy Simulations of turbulence, an implicitly resolved IW continuum in models may be within reach with appropriate choices of dissipation schemes, model resolutions, atmospheric forcing frequency, and enabling of nonhydrostatic dynamics. Regional IW models will be run to determine the impacts of resolution limitations and dissipation mechanisms on the modeled IW spectrum. Regional IW simulations and IW theory will be used to probe the dynamics underlying the IW spectrum and dissipation. Dissipation will be mapped using four different methods: as spectral fluxes computed using traditional Fourier techniques, as spectral fluxes computed using new coarse-graining techniques, as a residual of IW conversion rates and flux divergences, and as computed from model dissipation operators applied to high-frequency flow. Modeled energy dissipation rates will be compared to observation-based estimates of dissipation, from fine-structure methods applied to ARGO floats and ship-based CTD lines, and from microstructure measurements including those from a new NSF-funded set of EM-APEX floats.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.

该项目将使用最先进的高分辨率全球和区域重力波模式以及内部重力波的理论和观测，绘制内部重力波耗散和混合的时空地理以及基本动力学。这项研究将使用全球模式、区域模式、观测和理论，向未来迈出第一步，在未来，模式中自然产生IW耗散和混合，而不是参数化。该项目将支持东非肯尼亚的两所海洋和环境科学暑期学校，以补充自2015年以来每年开办的成功的西非暑期学校，累计有数百名非洲参与者和数十名美国参与者参加。首席调查人员假设，全球IW模型中的IW谱表示足够现实，模型可以对IW耗散的空间和时间分布以及IW引发的混合做出有用的预测。他们还假设，就像惯性子范围被湍流的大涡模拟隐式解析一样，模式中隐式解析的IW连续体可能是可以通过适当选择耗散方案、模式分辨率、大气强迫频率和启用非静力动力学来实现的。将运行区域IW模式，以确定分辨率限制和耗散机制对模拟的IW谱的影响。将使用区域IW模拟和IW理论来探索IW谱和耗散背后的动力学。将使用四种不同的方法绘制耗散图：作为使用传统傅立叶技术计算的光谱通量，作为使用新的粗粒化技术计算的光谱通量，作为IW转换率和通量发散的残差，以及根据应用于高频流的模型耗散算符计算。建模的能量耗散率将与基于观测的耗散估计进行比较，来自应用于ARGO浮标和船基CTD生产线的精细结构方法，以及来自微结构测量的结果，包括来自NSF资助的一组新的EM-APEX浮标的微结构测量。该奖项反映了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。