Collaborative Research: Quantifying Stratified Turbulence in Estuaries

合作研究：量化河口层状湍流

• 批准号: 0824871
• 负责人: Wayne Geyer
• 金额: $ 61.33万
• 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: 2008
• 资助国家: 美国
• 起止时间: 2008-09-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0824871&HistoricalAwards=false
• 关键词: Collaborative; Research; Quantifying; Stratified; Turbulence

Understanding turbulent mixing in strong stratification is a longstanding fundamental problem in fluid dynamics. The objectives of the proposed study are to determine the mechanisms responsible for estuarine mixing at large gradient Richardson number and to test turbulence parameterizations in this regime. Most high-quality data in this regime have resulted from laboratory measurements and direct numerical simulations. Field measurements of turbulent fluxes and dissipation rates are essential to understand turbulence at geophysically relevant scales. Estuaries are excellent laboratories for stratified turbulence because they combine strong stratification with strong tidal forcing. The measurements, simulations, and analyses will elucidate both stratified turbulence and estuarine dynamics. Measurements are conducted in two estuaries where the mixing is expected to be driven by distinctly different mechanisms. The Mobile Array for Sensing Turbulence (MAST) measurements will be complemented by three-dimensional Reynolds-averaged numerical simulations, which will place the measurements in context with the larger scale estuarine dynamics and permit evaluations of the turbulence parameterizations. The MAST is a new field instrument platform that can resolve key turbulent quantities with unprecedented spatial and temporal resolution. The objectives will be examined with MAST measurements of turbulent fluxes, dissipation rates, and length scales with high spatial and temporal resolution in fixed and underway modes, thus permitting both long time-series measurements and quantification of spatial variability. Three-dimensional numerical models play an increasingly important role as management tools in estuarine and coastal environments. The broader also impacts will include an explicit component to communicate the implications of this study to improve the turbulence-closure parameterizations in estuarine and coastal circulation models for interdisciplinary science and management applications.

理解强分层中的湍流混合是流体动力学中长期存在的基本问题。本研究的目的是确定大梯度理查森数下河口混合的机制，并测试该状态下的湍流参数化。该体系中的大多数高质量数据均来自实验室测量和直接数值模拟。湍流通量和耗散率的现场测量对于了解地球物理相关尺度的湍流至关重要。河口是分层湍流的绝佳实验室，因为它们结合了强烈的分层和强大的潮汐力。测量、模拟和分析将阐明分层湍流和河口动力学。测量是在两个河口进行的，预计混合是由截然不同的机制驱动的。湍流传感移动阵列（MAST）测量将得到三维雷诺平均数值模拟的补充，这将把测量置于更大规模的河口动力学背景下，并允许对湍流参数化进行评估。 MAST 是一种新型现场仪器平台，能够以前所未有的空间和时间分辨率解析关键的湍流量。目标将在固定和航行模式下通过湍流通量、耗散率和长度尺度的 MAST 测量进行检查，具有高空间和时间分辨率，从而允许长时间序列测量和空间变化的量化。三维数值模型作为河口和沿海环境的管理工具发挥着越来越重要的作用。更广泛的影响还将包括一个明确的组成部分，以传达本研究的影响，以改进跨学科科学和管理应用的河口和沿海环流模型中的湍流闭合参数化。