Research in Linear and Nonlinear Instability and Ocean Circulation Theory

线性和非线性不稳定性与海洋环流理论研究

• 批准号: 0925061
• 负责人: Joseph Pedlosky
• 金额: $ 32.35万
• 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: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0925061&HistoricalAwards=false
• 关键词: Research; Linear; Nonlinear; Instability; Ocean

The project consists of two themes: (1) Ocean Circulation Theory, in particular the flow around planetary scale islands including the effects of topographic "skirts" to the island, and (2) the linear and nonlinear dynamics of instabilities.In the context of the first theme the investigator, Dr. Pedlosky, will examine the nature of the circulation around islands and similar topographic features when topography produces closed, ambient, geostrophic contours of potential vorticity around the island. Preliminary investigation has demonstrated the strong influence of the topography in trapping fluid in a recirculation around the island and hence altering the measure of the interchange of fluid from one sub basin to another on each side of the island. This issue is of oceanographic and climatic relevance for flows as the Indonesian Throughflow. The process will be studied analytically, numerically and in the laboratory. For the second theme, the investigator will be guiding the research of a graduate student in a study of the instability of the frontal system produced by downwelling favorable wind stress on a coastal shelf. Preliminary results indicate that the resulting eddies can play a significant role in the cross shelf heat and mass transport. Broader Impacts: The proposed work takes up the study of novel and fundamental fluid mechanical processes of direct oceanographic relevance. The results of the research proposed here on the coastal instability problem will have applications to transport of tracers in the coastal zone and thus have ecological as well as dynamical consequences. The research associated with the flow around islands and through narrow gaps, in the context of the Indonesian Throughflow, has relevance to the planetary overturning circulation and hence pertinence to the problem of climate. Part of the research involves the guidance of a Ph.D. graduate student participating in the research (funded on another project) and will serve as a central element in his training and intellectual development. The interaction with Italian colleagues aids in the international exchange of scientific expertise.

该项目包括两个主题：（1）海洋环流理论，特别是行星尺度岛屿周围的流动，包括地形“裙”对岛屿的影响，以及（2）不稳定性的线性和非线性动力学。在第一个主题的背景下，研究员Pedlosky博士将研究岛屿周围的环流性质和类似的地形特征，当地形产生封闭，环境，地转等值线的位涡周围的岛屿。初步调查表明，地形在岛屿周围的回流中捕获流体，从而改变了岛屿两侧从一个子盆地到另一个子盆地的流体交换的测量结果。这个问题是海洋学和气候的相关性流作为印度尼西亚的洋流。该过程将在实验室中进行分析，数值研究。关于第二个主题，调查员将指导一名研究生研究沿海大陆架上有利的下行风应力所产生的锋面系统的不稳定性。初步结果表明，由此产生的涡旋可以发挥重要的作用，在跨大陆架的热量和质量输送。更广泛的影响：拟议的工作承担了直接海洋学相关的新的和基本的流体力学过程的研究。这里提出的沿海不稳定性问题的研究结果将有应用程序的示踪剂在沿海地区的运输，从而具有生态和动力学的后果。在印度尼西亚洋流的背景下，与岛屿周围和通过狭窄间隙的气流有关的研究与行星翻转环流有关，因此与气候问题有关。研究的一部分涉及博士的指导。研究生参与研究（由另一个项目资助），并将作为他的培训和智力发展的核心要素。与意大利同事的互动有助于科学专业知识的国际交流。