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

该项目将采用观测和建模相结合的方法，研究沿海分层羽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测量和系泊仪器将测量旧金山湾羽流在一系列风和河流排放条件下的环流和演变。结合数值模式模拟和观测，将量化海角下游羽流的动态平衡和停留时间。理想化的模拟将允许将结果扩展到参数空间，以了解影响沿海海洋海角背风处分层羽流分离和保留时间的控制动力学和条件。沿海羽流是陆架循环的关键组成部分，也是污染物、营养物、水团及其所含有机碳运输的重要管道。了解影响羽流分离和滞留时间的因素将有助于了解这些具有社会重要性的海洋组成部分的命运。复杂的海岸几何形状，如海角和海底堤岸，可能导致浮力海岸流的显著水动力扰动。这种羽流是大陆架环流、沿海海洋生物地球化学和海洋生态系统的关键组成部分，因此它们的动态和命运对于理解它们至关重要。该项目将利用船上、系泊和漂流的现场观测，结合现实和理想化的数值模拟研究，量化加利福尼亚州雷耶斯点附近的旧金山湾羽流在一系列风和河流排放条件下的相互作用。其主要目的是：(1)在一定的河流流量和强风条件下，获得羽流在海角附近的水文学、沿流和横流速度和输送的详细测量结果；(2)查明烟羽从海岸分离和在海角背风处产生涡流的条件；(3)对与产生的涡流有关的海角下游保留时间尺度进行量化；以及(4)研究控制烟羽与海角相互作用时远场动态的主要动量平衡。虽然羽状物覆盖了一小部分海洋表面，但它们是更大范围陆架环流的边界条件，因此它们的演变对于理解和真实地在模型中表示至关重要。该项目将导致更好地了解污染物、营养物和水团在海洋中的去向和运输，为科学界贡献观测数据集、模型和分析工具，并将为两名早期职业科学家提供关键的研究能力。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

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.