Collaborative Research: The Dynamics of Shoaling and Breaking Nonlinear Internal Waves and their Transport, Dispersion and Buoyancy and Momentum Balances

合作研究：浅滩和破裂非线性内波动力学及其传输、色散以及浮力和动量平衡

• 批准号: 0729636
• 负责人: Alberto Scotti
• 金额: $ 10.2万
• 依托单位: University of North Carolina at Chapel Hill
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-05-15 至 2014-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0729636&HistoricalAwards=false
• 关键词: Collaborative; Research; Dynamics; Shoaling; Breaking

Internal waves, which are waves formed between two layers of a stratified water column, are observed to propagate towards the coastline in most continental shelve regions. As these waves shoal, or are slowed by bottom friction, when entering into water depths of approximately one-half of the wave amplitude, their interaction with the bottom causes these waves to undergo transformations. Observations of across-shore transport and nutrient and plankton mixing suggest that nonlinear internal waves (NLIWs) play a critical role in the maintenance of some inner shelf benthic communities. However, the across-shore transport length scales, the dispersion rates and the fluxes of buoyancy, momentum and energy, and, thus, the potentially important influence of these waves on coastal circulation and ecosystems, have not yet been quantified. Oceanographers from Oregon State University and the University of North Carolina, with support from the Woods Hole Oceanographic Institute, will use a combined observational and numerical approach to quantify transport, dispersion, buoyancy and momentum fluxes, and flux divergences of shoaling NLIWs and determine their influence on the low-frequency circulation and density field in Massachusetts Bay. Their field observations will include deployments of a mooring array to quantify nonlinear internal wave fluxes, rapid shipboard surveys to study the evolution of individual waves from their generation point, through the region of shoaling, and to their demise near the coast, and dye injections and shipboard tracking to quantify scales of across-shore transport and rates of dispersion. In addition to field observations, a 'state-of-the-art', adaptive grid, nonhydrostatic, numerical model will be used to simulate nonlinear internal wave generation and evolution to compare the numerical output with the field observations and understand the detailed, three-dimensional evolution of these waves. Studying this process will provide an objective assessment of the significance of NLIWs relative to other physical processes in the coastal ocean. Understanding the mechanisms which transport and disperse water-borne materials (e.g., nutrients, pollutants, plankton) in the coastal ocean is a high priority objective for coastal physical oceanographic research and can have direct influence on environmental management.

内波是在分层水柱的两层之间形成的波，在大多数大陆架地区被观察到向海岸线传播。当这些波向浅滩移动，或被底部摩擦减慢时，当进入波幅约为一半的水深处时，它们与底部的相互作用会导致这些波发生变化。对跨岸迁移以及营养物和浮游生物混合的观察表明，非线性内波在维持一些内陆架底栖生物群落方面发挥着关键作用。然而，跨岸传输的长度尺度、分散率和浮力、动量和能量的通量，以及这些波对沿海环流和生态系统可能产生的重要影响，尚未量化。来自俄勒冈州立大学和北卡罗来纳大学的海洋学家将在伍兹霍尔海洋研究所的支持下，使用观测和数值相结合的方法来量化浅滩上的近海垃圾的传输、弥散、浮力和动量通量以及通量分歧，并确定它们对马萨诸塞湾低频环流和密度场的影响。它们的实地观测将包括部署系泊阵列以量化非线性内部海浪通量；进行快速船上勘测以研究单个海浪从其发生点、经过浅滩区域到其在沿海附近消亡的演变情况；以及进行染料注入和船上跟踪以量化跨岸运输的规模和分散率。除了现场观测，还将使用一种最先进的、自适应网格、非静力的数值模式来模拟非线性内波的产生和演变，以便将数值输出与现场观测结果进行比较，并了解这些波的详细的三维演变。研究这一过程将客观地评估非低收入海洋相对于沿海海洋其他物理过程的意义。了解沿海海洋中水生物质(如营养物、污染物、浮游生物)的运输和分散机制是沿海物理海洋学研究的一个高度优先目标，并可对环境管理产生直接影响。