Collaborative Research: River plume-cape interaction - Plume separation from the coastal wall, vorticity generation and fresh water retention

本项目将采用观测和模拟相结合的方法，研究分层的海岸卷流与海角的相互作用。加利福尼亚州雷耶斯角附近的高分辨率船上调查和系泊仪器将测量在一系列风和河流排放条件下旧金山弗朗西斯科湾羽流的环流和演变。结合数值模型模拟和观测将量化的动力平衡和停留时间的羽下游的海角。理想化的模拟将允许扩展的结果在参数空间，了解控制动力学和条件影响羽流分离和分层羽流在背风角在沿海海洋的保留时间。沿海羽流是陆架环流的一个关键组成部分，也是污染物、营养物、水团及其所含有机碳的重要输送管道。了解影响羽流分离和滞留时间的因素将有助于了解这些社会重要的海洋constituents.Complex的海岸几何形状，如海角和海底银行，可以导致重大的浮力沿海流的水动力扰动的命运。这些羽流是陆架环流和沿海海洋生物地球化学和海洋生态系统的关键组成部分，因此了解它们的动态和命运至关重要。该项目将量化的相互作用之间的弗朗西斯科湾羽在附近的点雷耶斯，加利福尼亚州，在一系列的风和河流排放条件下，使用船上，系泊，漂流实地观察，结合现实和理想化的数值模拟研究。主要目标是：（1）在一定范围的河流流量和风强迫条件下，获得羽流水文地理学、海角附近的沿着和横流速度和输送的详细测量值，（2）确定羽流与海岸分离的条件和海角背风处的涡流生成，（3）量化与生成的涡流相关的海角下游的滞留时间尺度，以及（4）研究当羽流与海角相互作用时控制远场动力学的主要动量平衡。虽然羽流包含一个小面积的海洋表面，他们是边界条件，为更大规模的陆架环流，因此，他们的演变是至关重要的理解和代表现实的模式。该项目将使人们更好地了解海洋中污染物、营养物质和水体的命运和迁移，为科学界提供观测数据集、模型和分析工具，该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响进行评估来支持审查标准。

This project will examine the interaction of a stratified coastal plume with a cape, using a combined observational and modeling approach. High-resolution shipboard surveys and moored instrumentation near Point Reyes, CA, will measure the circulation and evolution of the San Francisco Bay Plume under a range of wind and river discharge conditions. Combined numerical model simulations and observations will quantify the dynamical balances and residence times of the Plume downstream of the Cape. Idealized simulations will permit expansion of results across parameter space, to understand both the controlling dynamics and conditions affecting plume separation and retention times of stratified plumes in the lee of capes in the coastal ocean. Coastal plumes are a key component of shelf circulation, and important conduits for transport of pollutants, nutrients, water masses and the organic carbon they contain. Understanding the factors influencing plume separation and retention times will contribute to understanding fates of such societally important ocean constituents.Complex coastal geometries, such as capes and submarine banks, can lead to significant hydrodynamic disturbances of buoyant coastal flows. Such plumes are key components of shelf circulation and coastal ocean biogeochemistry and marine ecosystems, so their dynamics and fate are critical to understand. This project will quantify the interaction between the San Francisco Bay Plume in the vicinity of Point Reyes, CA, under a range of wind and river discharge conditions, using shipboard, moored, and drifter field observations, combined with realistic and idealized numerical modeling studies. The main objectives are to: (1) obtain detailed measurements of plume hydrography, along- and cross-stream velocities and transports near a cape, under a range of river discharge and wind-forcing conditions, (2) identify the conditions for plume separation from the coast and eddy generation in the lee of a cape, (3) quantify the retention time scales downstream of the cape associated with the generated eddies, and (4) investigate the dominant momentum balances that control far-field dynamics as the plume interacts with a cape. Although plumes encompass a small area of the ocean surface, they are the boundary condition for larger scale shelf circulation, and thus their evolution is critical to understand and represent realistically in models. This project will result in better understanding of the fate and transport of pollutants, nutrients and water masses in the ocean, contribute observational datasets, models, and analysis tools to the science community, and will provide critical research capacity for two early career scientists.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.