CAREER: Shoaling of Non-Linear Internal Waves over Gentle Slopes: Wave-Scale Interactions and Dissipative Processes

职业：缓坡上非线性内波的浅滩：波尺度相互作用和耗散过程

• 批准号: 0845558
• 负责人: Peter Diamessis
• 金额: $ 64.67万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-15 至 2015-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0845558&HistoricalAwards=false
• 关键词: CAREER; Shoaling; Non; Linear; Internal

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Nonlinear internal waves (NLIWs), ubiquitous features of the coastal ocean and lakes, are on the receiving end of an energy cascade initiated at large scales by the winds and tides in stratified natural water bodies. These waves transport this energy over 100km distances across gently sloping (shoaling) shelf regions and dissipate it remotely. Recent massive field-scale experiments in the South China Sea and the New Jersey Shelf have provided invaluable insight into the process of NLIW shoaling. Nonetheless, due to limitations of field measurements in space and time, a number of key questions on wave shoaling remain unanswered, namely in terms of the associated energy dissipation mechanisms, which are further complicated by the large-scale wave transformations due to variable bathymetry. To this end, small-scale numerical modeling is imperatively needed.The project aims at the use of a fully non-hydrostatic and nonlinear parallel spectral quadrilateral sub-domain penalty method model to numerically study shoaling of NLIWs over gentle slopes. The model enables the maximum possible scale separation between wave-scale and the small-scale dissipative processes in the wave interior/footprint with optimal resolution of the latter, allowing a Reynolds number as close as possible to the oceanic value. Simulations will focus on the basic physics of wave-scale transformations due to shoaling and their impact on the three-dimensional turbulent dissipative dynamics of the NLIW-induced benthic boundary layer and subsurface trapped recirculation cores. A close comparison with field data from the above sites (including a very richly documented set of observations from the South China Sea on NLIWs and trapped cores) will establish consistency checks for the simulations, flesh out the basic physics from the measurements and provide guidance for future deployments. Understanding the physics of turbulent dissipation in the NLIW footprint and interior is a crucial missing link in the closure of large-scale energy budgets in the ocean and lakes. Furthermore, the flow fields inside trapped cores and the NLIW-induced benthic boundary layer can drive powerful horizontal biota/nutrient transport and intense resuspension of bottom-lodged biogeochemical constituents, respectively. Beyond an enhanced description of the fundamental physics of wave shoaling, the project will offer the foundation for future investigations on how the flow fields within NLIWs directly interact with underwater ecology, acoustics and optics and impact water quality. Improved parameterizations of particulate re-suspension and near-bottom/surface dissipation may then be developed for use in larger-scale models and field data analysis.The close comparison with South China Sea field data will initiate an active long-term collaboration between Cornell and the University of Washington. All important numerical results will be disseminated to interested members of the oceanographic community via an internet database.Motivated by the advanced numerical methods embedded in the multi-domain solver, a tightly linked chain of educational activities seeks to initiate a reconsideration of the current paradigm in scientific computing education at the graduate/undergraduate level and to boost recruitment of high school students into science and engineering majors. Starting with graduate coursework, the proposed educational plan aims to create ocean model users who, although not developers, have a robust numerical and oceanographic expertise which is aligned with cutting edge computational methods. The restructuring of a sophomore-level course on scientific computing will allow undergraduate students to discover the potential of this research area and embrace it as a vehicle to complete their studies in the sciences and engineering, thereby establishing a consistent flux of future numerical modelers to the graduate ranks. A one-week high-school course module on internal wave simulation in lakes will introduce a diverse audience of high school students to computational modeling as an alternative to the traditional 'wet lab' and the option of future studies in applied computation in science and engineering.

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。非线性内波（NLIWs）是沿海海洋和湖泊普遍存在的特征，是分层自然水体中由风和潮汐在大尺度上引发的能量级联的接收端。这些波浪将这些能量传送到100公里以外的缓坡（浅滩）大陆架区域，并在遥远的地方消散。最近在南中国海和新泽西大陆架进行的大规模实地实验为了解NLIW浅滩化过程提供了宝贵的见解。然而，由于现场测量在空间和时间上的限制，关于波浪浅化的一些关键问题仍然没有得到解答，即相关的能量耗散机制，由于不同的水深测量导致的大规模波浪变换使这些问题进一步复杂化。为此，小规模数值模拟势在必行。该项目旨在利用完全非流体静力和非线性平行谱四边形子域惩罚方法模型，数值研究NLIWs在缓坡上的浅滩化。该模式使波浪尺度和波内部/足迹中的小尺度耗散过程之间尽可能实现最大的尺度分离，并使后者具有最佳的分辨率，从而使雷诺数尽可能接近海洋值。模拟将集中于浅滩引起的波浪尺度变换的基本物理特性及其对nliw诱导的底栖边界层和地下捕获再循环核心的三维湍流耗散动力学的影响。与上述地点的现场数据（包括南海nliw和被捕获岩心的一组非常丰富的观测记录）的密切比较将为模拟建立一致性检查，充实测量的基本物理，并为未来的部署提供指导。了解NLIW足迹和内部的湍流耗散物理是海洋和湖泊大规模能量收支关闭的关键缺失环节。此外，圈闭岩心内部的流场和nliw诱导的底栖边界层分别可以驱动强大的水平生物群/营养物质运输和底栖生物地球化学成分的强烈再悬浮。除了加强对波浪浅滩基本物理的描述外，该项目还将为未来研究NLIWs内的流场如何与水下生态、声学和光学直接相互作用并影响水质提供基础。颗粒再悬浮和近底部/表面耗散的改进参数化可以用于更大规模的模型和现场数据分析。与南中国海实地数据的密切比较将启动康奈尔大学和华盛顿大学之间积极的长期合作。所有重要的数值结果将通过互联网数据库分发给感兴趣的海洋学界成员。在多域求解器中嵌入的先进数值方法的激励下，一系列紧密相连的教育活动试图在研究生/本科阶段重新考虑科学计算教育的当前范式，并促进高中学生进入科学和工程专业的招聘。从研究生课程开始，拟议的教育计划旨在培养海洋模型用户，他们虽然不是开发人员，但具有强大的数值和海洋学专业知识，与尖端的计算方法保持一致。二年级科学计算课程的重组将使本科生发现这一研究领域的潜力，并将其作为完成其科学和工程研究的工具，从而为未来的数值建模师到研究生队伍建立一致的通量。为期一周的关于湖泊内波模拟的高中课程模块将向不同的高中生介绍计算建模，作为传统“湿实验室”的替代方案，以及未来科学和工程应用计算研究的选择。