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: 2319144
• 负责人: Kurt Polzin
• 金额: $ 88.44万
• 依托单位: Woods Hole Oceanographic Institution
• 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=2319144&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.

该项目将利用最先进的高分辨率全球和区域重力波模型以及重力波的理论和观测，绘制内部重力波（IW）耗散和混合的时空地理图，以及潜在的动力学。 该研究将采用全球模型、区域模型、观测和理论，朝着未来 IW 耗散和混合在模型中自然出现而无需参数化的方向迈出第一步。该项目将支持东非肯尼亚的两所海洋与环境科学暑期学校，以补充自 2015 年以来每年举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与。首席研究员假设，全局 IW 模型中 IW 频谱的表示足够真实，模型可以对 IW 耗散的空间和时间分布以及推而广之的 IW 引起的混合做出有用的预测。他们还假设，正如湍流大涡模拟隐式解析了惯性子范围一样，通过适当选择耗散方案、模型分辨率、大气强迫频率和启用非静水动力学，模型中隐式解析的 IW 连续体可能是可以实现的。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 理论将用于探讨 IW 频谱和耗散背后的动态。 耗散将使用四种不同的方法进行映射：使用传统傅立叶技术计算的光谱通量、使用新的粗粒度技术计算的光谱通量、IW 转换率和通量散度的残差、以及根据应用于高通量的模型耗散算子计算。 -频率流。建模的能量耗散率将与基于观测的耗散估计进行比较，这些估算来自应用于 ARGO 浮体和船基 CTD 线的精细结构方法，以及微观结构测量，包括来自 NSF 资助的一套新的 EM-APEX 浮体的测量。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。