Collaborative Research: Lee Waves and Turbulence Forced by the Kuroshio

合作研究：李波和黑潮引起的湍流

• 批准号: 1829190
• 负责人: Eric Kunze
• 金额: $ 46.69万
• 依托单位: NorthWest Research Associates, Incorporated
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1829190&HistoricalAwards=false
• 关键词: Collaborative; Research; Lee; Waves; Turbulence

Roughly 1 TW is input into the ocean circulation by wind-work. How this balanced energy is dissipated to maintain steady state remains uncertain but is important for correctly modeling balanced energy pathways in ocean general circulation models. Loss to lee-wave generation followed by turbulence production has been hypothesized to account for 20-75 percent. The research will clarify lee-wave generation and the waves' role in dissipating vs. redistributing balanced energy. Results from this project will be presented at conferences and published in peer-reviewed journals to make them available to the wider scientific community. Data will be archived at public sites at University of Washington (UW) Applied Physics Laboratory (APL) and Northwest Research Associates. An improved model parameterization for the dissipation and redistribution of balanced flows and induced mixing by lee-wave generation is an expected outcome. The project will support a postdoctoral researcher in data analysis and internal-wave physics. Seattle K-12 classroom visits and active engagement with UW and local science centers is planned. The project will also contribute to the summer program for UW undergraduate students and the annual Pacific Science Center Polar Science Weekend.Lee-wave generation (0.2-0.75 TW) and bottom drag (~0.25 TW) are two hypothesized sinks. The passage of the Kuroshio through Tokara Strait affords an accessible case to evaluate lee-wave generation and dissipation that impact a major western boundary current. It has been assumed that lee-wave generation is lost to turbulence. However, measurements in Antarctic Circumpolar Current jets find that turbulent dissipation rates fall short of predictions by as much as an order of magnitude. Measurements will be made to study internal lee-wave generation and evolution, hydraulic jumps, turbulence and water-mass transformation where the Kuroshio crosses a seamount chain in Tokara Strait. Line-arrays of chi-augmented EMAPEX profiling floats will be deployed at across-stream locations upstream of the seamount chain to be swept across by the Kuroshio, obtaining along-stream/depth sections from the surface to the bottom ( 600 m depth), and from up- to downstream of the shoal topography with a focus on the flow structure and turbulence in the lee. These measurements will address whether lee-wave generation and bottom drag represent major sinks for balanced flows. These measurements will offer a more complete assessment of lee-wave generation and the fate of lee waves than has hitherto been performed.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

大约有1太瓦的风输入到海洋环流。这种平衡的能量如何耗散以维持稳定状态仍然不确定，但对于正确模拟海洋环流模式中的平衡能量路径非常重要。据推测，背风波产生的损失以及随后的湍流产生占20- 75%。这项研究将澄清背风波的产生和波在消散与重新分配平衡能量中的作用。该项目的成果将在会议上介绍，并在同行评审的期刊上发表，以便更广泛的科学界可以使用。数据将存档在华盛顿大学（UW）应用物理实验室（APL）和西北研究协会的公共站点。一个改进的模型参数化的耗散和平衡流的再分配和诱导混合的背风波生成是一个预期的结果。该项目将支持数据分析和内波物理学的博士后研究人员。西雅图K-12教室访问和积极参与与华盛顿大学和当地科学中心的计划。该项目还将为华盛顿大学本科生的暑期项目和一年一度的太平洋科学中心极地科学周末做出贡献。背风波生成（0.2-0.75 TW）和底部阻力（~0.25 TW）是两个假设的汇。黑潮通过吐噶喇海峡的通道提供了一个可访问的情况下，以评估背风波的产生和消散，影响一个主要的西部边界流。人们已经假定，背风波的产生是失去了湍流。然而，南极绕极流射流的测量发现，湍流耗散率达不到预测的数量级。将进行测量，以研究内背风波的产生和演变，水力跃变，湍流和水团的变化，在黑潮穿越托卡拉海峡海山链。将在将被黑潮扫过的海山链上游的跨流位置部署chi-augmented EMAPEX剖面浮标线阵，获取从表面到底部（600米深）以及从浅滩地形的上游到下游的顺流/深度剖面，重点是背风面的流动结构和湍流。 这些测量将解决是否背风波生成和底部阻力代表平衡流的主要汇。这些测量将提供一个更完整的评估背风波的产生和背风波的命运比迄今为止执行。这个奖项反映了NSF的法定使命，并已被认为是值得支持的，通过评估使用基金会的知识价值和更广泛的影响审查标准。

项目成果

Energy Sinks for Lee Waves in Shear Flow

• DOI: 10.1175/jpo-d-19-0052.1
• 发表时间: 2019-10
• 期刊: Journal of Physical Oceanography
• 影响因子: 3.5
• 作者: E. Kunze;R. Lien