Quantification of energy cascade of internal gravity waves with varying spectral slopes

具有不同谱斜率的内部重力波能量级联的量化

• 批准号: 2241495
• 负责人: Yulin Pan
• 金额: $ 52.33万
• 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: 2023-03-15 至 2026-02-28
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2241495&HistoricalAwards=false
• 关键词: Quantification; energy; cascade; internal; gravity

Vertical density differences in the ocean support 'internal' waves (waves in the ocean's interior) that have different periods. The energy of these internal waves often trickles down to smaller waves that eventually dissipate, a process known as the energy cascade. The cascade process can lead to mixing, and determines the heat and salt balances and general circulation of the ocean. This project will investigate this energy cascade through theory, modeling, and data analysis. The existing theory of the energy cascade, based on the turbulence produced by internal waves, will be improved in this study (with existing controversies resolved) and extended to more realistic situations. Subsequent validation of the improved theory will be done with high-resolution regional model simulations. The project will also apply this improved theory to a global model simulation and establish a geographic map of dissipation . Broader impacts include enhancements to global climate models and regional models. The theoretical improvement will inform a range of physical applications and mathematical studies of internal wave turbulence. Annual presentations are planned for the turbulence community. The work supports an early career PI, a postdoc, and teaching and public outreach through the Coastal Ocean Environment Summer School in Ghana and public lectures on the history of fluid mechanics through programs at the UM Museum of Natural History.The proposed project will establish a comprehensive understanding of the downscale energy cascade of IGW spectra with variable spectral slopes, from both theoretical and computational considerations. Research tasks include: 1) Development of theoretical formulations of energy cascade for spectra with varying slopes in the wave turbulence theory framework, which will be guided and confirmed by simulations of the kinetic equation. 2) Further improvement of the regional MITgcm simulation of 24-32 degrees N, 193-199 degrees E to better match the spectra from McLane profiler measurements (through adjustment of model resolution and K-profile parameterization), computation of the modeled energy cascade with comparison to theoretical results obtained from task 1. 3) Application of the traditional/new finescale parameterization to a global MITgcm model to establish a geographic map of turbulent dissipation rate, and comparison of the results to those from microstructure measurements. The new finescale parameterization formulation from spectra that more closely match spectra from measurements, together with improved regional models through tuning of K-profile parameterization, will lead to fundamentally improved diapycnal mixing parameterizations in ocean models.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.

海洋中的垂直密度差异支持具有不同周期的“内”波（海洋内部的波）。这些内波的能量通常会滴落成较小的波，最终消散，这一过程称为能量级联。级联过程会导致混合，并决定热量和盐的平衡以及海洋的整体循环。该项目将通过理论、建模和数据分析来研究这种能量级联。现有的基于内波产生的湍流的能量级联理论将在本研究中得到改进（解决现有争议）并扩展到更现实的情况。改进理论的后续验证将通过高分辨率区域模型模拟来完成。该项目还将把这一改进的理论应用到全球模型模拟中，并建立耗散地理图。更广泛的影响包括增强全球气候模型和区域模型。理论改进将为内波湍流的一系列物理应用和数学研究提供信息。计划为湍流界举办年度演讲。这项工作支持早期职业 PI、博士后以及通过加纳沿海海洋环境暑期学校的教学和公共宣传以及通过密歇根大学自然历史博物馆的项目举办的流体力学历史公开讲座。拟议的项目将建立一个从理论和计算的角度全面理解具有可变光谱斜率的 IGW 光谱的小尺度能量级联。研究任务包括： 1）在波动湍流理论框架中发展不同斜率谱的能量级联理论公式，这将通过动力学方程的模拟来指导和证实。 2) 进一步改进北纬 24-32 度、东经 193-199 度的区域 MITgcm 模拟，以更好地匹配麦克莱恩剖面仪测量的光谱（通过调整模型分辨率和 K 剖面参数化），计算建模的能量级联与任务 1 获得的理论结果进行比较。 3) 将传统/新的细尺度参数化应用于全局 MITgcm 模型，以建立湍流耗散率的地理图，并将结果与来自微观结构测量的那些。新的光谱精细参数化公式与测量光谱更加匹配，再加上通过调整 K 剖面参数化改进的区域模型，将从根本上改进海洋模型中的二重混合参数化。该奖项反映了 NSF 的法定使命，并被视为值得通过使用基金会的智力优点和更广泛的影响审查标准进行评估来支持。

项目成果

Energy cascade in the Garrett–Munk spectrum of internal gravity waves

• DOI: 10.1017/jfm.2023.862
• 发表时间: 2023-05
• 期刊: Journal of Fluid Mechanics
• 影响因子: 3.7
• 作者: Yue Wu;Yulin Pan

Probing the Nonlinear Interactions of Supertidal Internal Waves Using a High-Resolution Regional Ocean Model

使用高分辨率区域海洋模型探测超潮内波的非线性相互作用

• DOI: 10.1175/jpo-d-22-0236.1
• 发表时间: 2024
• 期刊: Journal of Physical Oceanography
• 影响因子: 3.5
• 作者: Skitka, Joseph;Arbic, Brian K.;Thakur, Ritabrata;Menemenlis, Dimitris;Peltier, William R.;Pan, Yulin;Momeni, Kayhan;Ma, Yuchen
• 通讯作者: Ma, Yuchen