Collaborative Research: Mixing and Circulation in a Buoyant Coastal Plume

合作研究：漂浮的沿海羽流中的混合和循环

• 批准号: 0220345
• 负责人: Robert Houghton
• 金额: $ 47.77万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-01 至 2007-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0220345&HistoricalAwards=false
• 关键词: Collaborative; Research; Mixing; Circulation; Buoyant

0220345 HoughtonMixing and circulation in the Delaware Coastal Current (DCC), a buoyant coastal jet, will be studied using a combination of numerical modeling and field work (moorings, rapid surveys, and purposeful dye releases) followed by analysis and interpretation of results from the two approaches. Working hypotheses are that mixing between the coastal buoyant discharge and ambient shelf waters is larger during upwelling than downwelling events, that this mixing during upwelling is primarily concentrated at the offshore plume boundary, and that the conservation of buoyancy is principally a balance between horizontal advection and vertical diffusion. Moorings will include standard current meters and bottom-mounted acoustic Doppler current profilers (ADCPs). There will be 5 moorings, three parallel to the DCC and three perpendicular. Multiple conductivity-temperature-depth recorders (CTDs) and temperature sensors will also be deployed on both taut and slack moorings. At the northernmost mooring, two ADCPs will allow estimation of the Reynolds stresses using Stacey's method. ADCP bin spacing will be 0.5 m allowing resolution of 1m eddies. Forty-five kilograms of Rhodamine dye will be released during each upwelling or downwelling event selected for study. This dye will be traced for 4-5 days. There will be two cruises and mooring deployments. One upwelling dye study will occur during year 1 and one upwelling and one downwelling experiment during year two. A previously utilized version of ECOM3d, configured for the DCC, will be used to analyze the dye study results. Significant effort will be devoted to comparing different turbulent closure schemes. After the model is calibrated, it may be used for sensitivity studies. Careful comparison and interpretation of field and model results will conclude the study.

0220345霍顿将结合数值模拟和实地工作(系泊、快速调查和有目的的染料释放)研究特拉华海岸流中的混合和环流，然后对两种方法的结果进行分析和解释。工作假设是，在上升流期间，沿海浮力排放与周围陆架水域之间的混合比下降流事件中的混合更大，上升流期间的混合主要集中在离岸羽流边界，浮力守恒主要是水平平流和垂直扩散之间的平衡。系泊设备将包括标准海流计和底部安装的声学多普勒海流剖面仪(ADCP)。将有5个系泊平台，其中3个与DCC平行，3个垂直。多个电导率-温度-深度记录器(CTD)和温度传感器也将部署在绷紧和松弛的系泊设备上。在最北的系泊处，两个ADCP将允许使用Stacey的方法估计雷诺应力。ADCP仓间距为0.5米，允许分辨率为1米的涡流。在选定进行研究的每个上升流或下降流事件期间，将释放45公斤罗丹明染料。这种染料会被追踪4-5天。将有两次巡航和系泊部署。一项上升流染料研究将在第一年进行，一项上升流和一项下降流实验将在第二年进行。为DCC配置的之前使用的ECOM3d版本将用于分析染料研究结果。将致力于比较不同的湍流封闭方案。模型校准后，可用于敏感性研究。对现场和模型结果的仔细比较和解释将得出该研究的结论。