Collaborative Research: Mixing and Circulation in a Buoyant Coastal Plume

0220345 houghton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）对特拉华海岸流（DCC）的混合和环流进行研究，然后对两种方法的结果进行分析和解释。目前的假设是，在上升流期间，沿海浮力排放与周围陆架水之间的混合比下升流事件更大，上升流期间的混合主要集中在近海羽流边界，浮力的保持主要是水平平流和垂直扩散之间的平衡。系泊将包括标准的电流计和底部安装的声学多普勒电流分析器（ADCPs）。将有5个系泊，三个平行于DCC和三个垂直。多个电导率-温度-深度记录仪（ctd）和温度传感器也将部署在紧系和松弛系泊上。在最北端系泊处，两个adcp将允许使用Stacey的方法估计雷诺兹应力。ADCP仓间距为0.5 m，允许1m漩涡的分辨率。45公斤罗丹明染料将在每次上涌或下涌事件中释放。这种染料要留4-5天。将有两次巡航和系泊部署。一个上升流染料研究将在第一年进行，一个上升流和一个下升流实验将在第二年进行。为DCC配置的以前使用的ECOM3d版本将用于分析染料研究结果。将花大量的精力来比较不同的湍流关闭方案。模型校正后，可用于敏感性研究。仔细比较和解释现场和模型的结果将结束研究。

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.