Nonlinear Internal Waves on the Inner Continental Shelf: Their Dynamics and Associated Cross-Shelf Fluxes

内大陆架上的非线性内波：它们的动力学和相关的跨大陆架通量

• 批准号: 0424742
• 负责人: Robert Weller
• 金额: --
• 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: 2004
• 资助国家: 美国
• 起止时间: 2004-10-01 至 2007-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0424742&HistoricalAwards=false
• 关键词: Nonlinear; Internal; Waves; Inner; Continental

ABSTRACTOCE-0424742In many coastal regions large amplitude, high-frequency internal waves and internal tidal bores have been observed to propagate onshore. Because of their large amplitude, these shoaling waves carry energy from their generation regions towards the coast, and transport mass and buoyancy between the outer and inner continental shelf. Field observations suggest that these waves may be critical for transporting larval stage benthic organisms from the continental shelf back to nearshore regions, where they can settle at appropriate habitats. The waves may also significantly contribute to the cross-shore transport and dispersion of nutrients and pollutants from sewage outfalls. In some regions of the coastal ocean, particularly where winds and upwelling are weak, the cross-shore transport of momentum and buoyancy due to nonlinear internal waves may be a dominant term in the inner shelf momentum and buoyancy budgets. While field evidence suggests that the importance of nonlinear internal waves on the inner shelf are compelling, detailed investigations of the dynamics of these waves and their associated fluxes are lacking and have yet to be quantified. In this project, a researcher from the Woods Hole Oceanographic Institution will examine the cross-shore momentum balance of shoaling and nonlinear internal waves, as well as quantify the fluxes of mass, buoyancy, and the Lagrangian transports associated with these waves. In addition to the field observations that were collected in the summer and fall of 1996 and 1997 off of Mission Beach, California, the Principle Investigator will utilize a two-dimensional, rotating, nonlinear, non-hydrostatic model for his investigation. The numerical model will be run using a domain with the same cross-shore geometry as that of the field observations and will be forced within the internal wave field observed at the offshore mooring site. To assess the ecological importance of nonlinear internal waves, the cross-shore transport of plankton through internal wave activity will be quantified and compared to other transport mechanisms (e.g, upwelling relaxation or coastal trapped waves). In addition, the feedback between nonlinear shoaling, breaking internal waves, and the inner shelf density field will also be quantified to determine their mechanistic relevancy to the inner shelf momentum and buoyancy budgets. Broader Impacts: The results gathered from this project will not only yield a better understanding of the fate of larvae and nutrients along the coast, but also clarify the fate of pollutants from rain runoff in populated areas. Because of this project's applicability to the design of sewage outfalls, a report of the conclusions from this study will be presented to the City of San Diego Metropolitan Wastewater Department, who operates a sewage outfall facility off of Pt. Loma, just south of where these field observations were made.

在许多沿海地区，已经观察到大振幅高频内波和内涌潮向岸上传播。 由于其振幅大，这些浅化波携带能量从其生成区域向海岸，并在外大陆架和内大陆架之间输送质量和浮力。 实地观察表明，这些波浪可能是将幼虫阶段的底栖生物从大陆架运回近岸区域的关键，在那里它们可以在适当的生境定居。 波浪也可能显著地促进来自污水排放口的营养物和污染物的跨海岸运输和扩散。 在沿海海洋的某些区域，特别是在风和上升流较弱的地方，由于非线性内波引起的动量和浮力的跨岸输运可能是内陆架动量和浮力预算中的主导项。 虽然现场证据表明，非线性内波的重要性，内大陆架是令人信服的，详细调查这些波的动力学及其相关的通量是缺乏和尚未被量化。 在这个项目中，来自伍兹霍尔海洋研究所的一名研究人员将研究浅滩和非线性内波的跨岸动量平衡，以及量化与这些波相关的质量通量、浮力和拉格朗日输运。 除了1996年和1997年夏季和秋季在加州的使命海滩外收集的现场观察外，首席研究员将利用二维、旋转、非线性、非流体静力学模型进行研究。 数值模型将使用具有与现场观测相同的跨岸几何形状的域运行，并将在海上系泊现场观测到的内波场中强制运行。 为了评估非线性内波的生态重要性，通过内波活动的跨海岸浮游生物运输将被量化，并与其他运输机制（例如，上升流松弛或沿海被困波）进行比较。 此外，非线性变浅，打破内波，和内大陆架密度场之间的反馈也将被量化，以确定其机械相关的内大陆架动量和浮力预算。更广泛的影响：从这个项目中收集的结果不仅将更好地了解沿着幼虫和营养物质的命运，而且还将澄清人口稠密地区雨水径流中污染物的命运。 由于该项目适用于污水排放口的设计，本研究的结论报告将提交给圣地亚哥市大都会污水处理部门，该部门在Pt附近运营污水排放设施。洛马，就在这些实地观察的南方。