Internal Tide and Waves on the Oregon Continental Shelf

俄勒冈大陆架的内潮和波浪

• 批准号: 0623132
• 负责人: Murray Levine
• 金额: $ 40.11万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-15 至 2010-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0623132&HistoricalAwards=false
• 关键词: Internal; Tide; Waves; Oregon; Continental

The goal of this research project is to improve our understanding of the generation, propagation and dissipation of the oceanic internal tide on the continental shelf. The internal tide is an internal wave generated when the stratified ocean is forced over bathymetric relief by the barotropic tide. The internal tide that propagates across the shelf toward the shore can become quite complex and often develops into packets of nonlinear internal waves. The internal tide is a major source of variability on continental shelves around the world and is potentially an important source of energy for generating the turbulence responsible for mixing scalars and momentum. It is important to determine the role the internal tide plays in the energy and momentum budgets to better understand and model coastal ocean circulation. It is also important to know the contribution of the internal tide to processes that lead to cross-shelf transport of mass, which includes nutrients, larvae, and sediment. The specific scientific objectives of this project are to: characterize the amplitude, energy flux, and vertical structure of the internal response near tidal frequencies on the shelf, describe the vertical structure and propagation characteristics of the nonlinear internal tide as it propagates across the shelf, quantify the internal wave background frequency continuum on the shelf, and assess the potential impact of the internal tide on cross-shelf transport of biota and sediment and parameterizations of mixing used in current numerical models of coastal circulation. The approach to accomplish these objectives is to analyze the wealth of observations made off the Oregon coast during three comprehensive experiments in summer 1999, summer 2001 and winter 2003. Previously funded analysis focused on the low-frequency wind-forced circulation. This project focuses on the internal tide and higher frequencies. A two-dimensional primitive equation numerical model of the internal tide will be used as a tool to guide the analysis. The purpose of the model is to help us understand the basic physical balances that are consistent with the observations.Broader Impacts: The internal tide contributes to the dissipation of energy and mixing, however, the tide is typically not explicitly included in circulation models. Research, such as that proposed here, will help determine the potential importance of internal tide, eventually leading to direct inclusion of the tide into models, or modification of the existing parameterization used for mixing. Nonlinear internal wave packets may be important in transporting biota, such as larvae, onshore, and sediment offshore. This study will provide some insight into these processes, including information on their spatial and temporal variability. There is much interest in understanding the impacts of cross-shelf transport on biological processes and the ecology of the Oregon shelf and coast. The data analysis methods and the numerical model developed here will be used directly in the education of graduate students in a class being offered by Levine on the internal tide at Oregon State University during the 2006-07 academic year. This class will be taken by graduate students pursuing PhDs in oceanography. The students will learn about the internal tide by running the model and analyzing observations for themselves.

该研究项目的目的是提高我们对大陆架上海洋潮汐的产生，传播和耗散的理解。当分层海洋被压缩潮水迫使分层的海洋缓解时，内部潮汐是产生的。在整个架子上朝向岸边传播的内部潮汐可能会变得非常复杂，并且经常发展成非线性内部波的包装。内部潮汐是世界各地大陆货架上可变性的主要来源，并且可能是产生负责混合标量和动量的湍流的重要能源。确定内部潮汐在能源和动量预算中的作用很重要，以更好地理解和建模沿海海洋循环。同样重要的是要了解内部潮汐对导致质量交叉运输的过程的贡献，包括营养素，幼虫和沉积物。该项目的具体科学目标是：表征架子上潮汐频率附近的内部响应的幅度，能量和垂直结构，描述非线性内部潮汐的垂直结构和传播特性，因为它在整个架子上传播时，它会在架子上传播，并量化内部波动的内部波动频率和储层的内部延迟，并评估架子上的内部延迟及其在架子上的延迟，并在架子上进行延伸，并在架子上进行了延伸，并在架子上进行了繁殖，并在架子上进行了延伸，并在架子上进行了延伸的序列及其在架子上的影响。在当前沿海循环的数值模型中。实现这些目标的方法是分析1999年夏季，2001年夏季和2003年夏季的三个综合实验中，在俄勒冈州海岸上进行的大量观察。该项目着重于内部潮汐和更高的频率。内部潮汐的二维原始方程数值模型将用作指导分析的工具。该模型的目的是帮助我们了解与观测值一致的基本物理平衡。BRODER的影响：内部潮汐有助于耗散能量和混合，但是，潮汐通常并未明确包含在循环模型中。诸如此处提出的研究将有助于确定内部潮汐的潜在重要性，最终导致将潮汐直接纳入模型，或修改用于混合的现有参数化。非线性内波包在运输幼虫，陆上和近海沉积物等生物群中可能很重要。这项研究将为这些过程提供一些见识，包括有关其空间和时间变异性的信息。了解跨架运输对生物过程以及俄勒冈货架和海岸生态学的影响很大。此处开发的数据分析方法和数值模型将直接用于莱文在2006-07学年的俄勒冈州立大学的内部潮流中提供的研究生的教育。该课程将由攻读海洋学博士学位的研究生参加。学生将通过运行模型并自己分析观察结果来了解内部潮流。