Collaborative Research: Internal Waves across the Pacific

合作研究：跨太平洋的内波

• 批准号: 0424717
• 负责人: Matthew Alford
• 金额: --
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-10-01 至 2009-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0424717&HistoricalAwards=false
• 关键词: Collaborative; Research; Internal; Waves; across

0424717Intellectual Merit:The wind and the tides input the overwhelming majority of the energy into the internal-wave field, whose breaking is the primary driver of turbulent mixing in the ocean. It has recently become clear that much of the input energy takes the form of low-mode internal waves, which can propagate far ( 1000 km). It follows that, in principle, the global magnitude and distribution of turbulent mixing depends primarily on the sources and subsequent evolution of the propagating, low-mode internal waves. New interpretation of historical moorings, new observations from the Hawaii Ocean Mixing Experiment, and new numerical modeling results suggest that long-range wave propagation is strongly modulated and, at times, completely disrupted, by interactions with other internal waves, topography, and the mesoscale background. This project seeks to better understand the processes that govern long-range internal-wave propagation, with an ultimate long-range goal of determining the global distribution, magnitude and time-dependence of internal-wave driven mixing. The project will integrate three principal activities:o Observational Study of Long-range Propagation. A line of six Moored Profilers extending northward from Hawaii, spanning 26N-37N, will measure velocity and density from 100-2600 m down to 2-m scales, for 50 days. Ship-based sensors will measure upper-ocean shear and density along this track, obtaining 2 broad snapshots and three spring-tide 5-day time series at three latitudes. Energy, energy flux, and dissipation rate (from overturning scales) will be computed at all measurement locations. This experiment will enable a coherent picture of the long-range propagation of the tide over about 1200 km. o Numerical simulations. A series of hypothesis-driven, controlled numerical experiments will be conducted to optimally design the observations, and to investigate dynamical processes that can drain energy from a propagating internal tide.o Historical Data Analysis of moored records and upper-ocean shear from ship-based instruments will be done to characterize the spatial dependence of internal-wave shear, ray slopes, energy and flux, and to provide large-scale observational context for the above simulations. Broader Impacts:This work has four vital implications for the broader community. First, a dynamical understanding of the resultant geography of mixing is required for accurate understanding and modeling of the large-scale circulation in past, present and future climates. The combination of observations and process-oriented modeling will contribute to the knowledge required to construct physically motivated mixing parameterizations that are dynamically coupled to the large-scale circulation. Second, satellite altimetry has been increasingly seen as an important community resource for monitoring global internal-wave fields. Careful comparison of altimetric results and subsurface observations will help interpretation of altimetric data. Third, the 50-day, 1200-km array is a prototype observing system for long-term monitoring not only of the internal tide and associated turbulence, but of many other mesoscale phenomena. Fourth, the proposed work will contribute to education by providing support and mentoring for two post-docs, and at-sea experience for several graduate students. Results will be shared at national and international workshops and conferences.

0424717Intlectual的优点：风与潮汐输入了绝大多数能量到内波场，其破裂是海洋中湍流混合的主要驱动力。最近很清楚，许多输入能的形式采用了低模式内波的形式，这可以传播远处（1000 km）。因此，原则上，湍流混合的全局幅度和分布主要取决于传播低模式内波的来源和随后的演变。对历史系泊设备的新解释，夏威夷海洋混合实验的新观察结果以及新的数值建模结果表明，远距离波传播经过强烈调制，有时会通过与其他内部波，地形和中镜背景的相互作用而完全破坏。该项目旨在更好地了解控制远程内波传播的过程，其最终的远程目标是确定内波动驱动混合的全球分布，大小和时间依赖性。该项目将整合三个主要活动：o远程传播的观察性研究。跨夏威夷向北延伸的六个停泊的剖道师的线，跨越26N-37N，将在50天的速度和密度从100-2600 m降至2 m尺度上的速度和密度。基于船舶的传感器将沿此轨道测量上海上的剪切和密度，在三个纬度上获得2个宽阔的快照和三个春季潮汐5天的时间序列。能量，能量通量和耗散速率（来自倾覆量表）将在所有测量位置计算。该实验将使潮汐在约1200公里以上的潮汐之间的远距离传播进行连贯的图片。 o数值模拟。将进行一系列由假设驱动的，受控的数值实验，以最佳设计观察结果，并研究可以从传播内部潮汐中耗尽能量的动力学过程。更广泛的影响：这项工作对更广泛的社区具有四个至关重要的影响。首先，需要对混合所得地理的动态理解，才能准确理解和建模过去，现在和将来的气候中的大规模循环。观测和面向过程的建模的组合将有助于构建具有动态动机的混合参数化所需的知识，这些参数化与大规模循环动态耦合。其次，卫星高度测定越来越被视为监测全球内波领域的重要社区资源。仔细比较高度的结果和地下观察结果将有助于解释高度数据。第三，50天，1200公里的阵列是一个原型观察系统，用于长期监测内部潮汐和相关的湍流，而且在许多其他中尺度现象中。第四，拟议的工作将通过为两位后的两名后的支持和指导提供支持和指导，并为几位研究生提供AT-SEA经验。结果将在国家和国际研讨会和会议上共享。