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.

该项目将使用最新的高分辨率全球和区域IW模型以及IWS的理论和观察结果来绘制内部重力波（IW）耗散和混合的时空地理以及基础动力学。 该研究将采用全球模型，区域模型，观察和理论，迈出第一步，迈向了IW耗散和混合自然在模型中自然出现的未来，而不会被参数化。该项目将支持东非肯尼亚海洋和环境科学上的两所暑期学校，以补充自2015年以来每年都在每年开展的成功的西非暑期学校，并累积了几百名非洲参与者和数十名美国参与者的参与。并且，通过扩展，IW引起的混合。他们还假设，大型涡流模拟隐含地解决了惯性的子句法，模型中隐式解决的IW连续体可能与耗散方案，模型分辨率，大气强迫频率以及启用非漏气动力学的适当选择有关。将运行区域IW模型，以确定分辨率限制和耗散机制对建模IW频谱的影响。区域IW模拟和IW理论将用于探测IW频谱和耗散的动力学。 耗散将使用四种不同的方法进行映射：作为使用传统傅立叶技术计算的光谱通量，作为使用新的粗粒技术计算的光谱通量，作为IW转换速率和磁通差的残差，以及根据应用于高频流量的模型耗散器计算的。将建模的能量耗散率与基于观察的耗散估计值，从应用于Argo浮标和基于船舶的CTD线的精细结构方法以及微观结构测量以及来自NSF资助的EM-APEX Float集中的微观结构测量值进行比较。这是NSF的法定任务和经过评估的范围。