Toward a more complete understanding of coastal upwelling dynamics

这项研究将探索沿海上升流的普遍海洋现象，在这种现象中，营养丰富的水主要通过海面上的风被抽向水面。这一现象对世界不同地区渔业的面貌产生了重要影响。这项研究将使用数学模型，这些模型代表了上升流在倾斜的大陆架上的理想条件。尽管理想化了，但模型将增加三维方面和由不同的水密度，即浮力引起的动力效应。结果将在一个包括大陆架斜率、浮力效应和地球自转影响的框架内进行预测。作为更广泛的影响，这项研究预计将提高对影响海岸附近溶解和悬浮物质的过程的理解。它还将培养一名博士后学者、一名研究生和两名本科生。该提案将探索垂直分层海洋条件下海岸上升流的三维路径。这项研究将使用一系列理想化的3D数值模拟，对比与埃克曼动力学相关的常规2D描述。模拟将被放置在一个整体框架中，该框架考虑了风驱动的环流、(亚)中尺度湍流和边界层过程之间的相互作用。因此，模拟将通过基于斜率Burger数的框架来处理表面和底部边界层之间的耦合，斜率Burger数比较浮力和科里奥利频率。预计Burger数值将诊断出岸上水流是沿着水柱底部还是在水柱内部。这项研究的一个特殊性是，除了检查三维结构外，还评估了斜压不稳定在沿等轴线涡动形成上升流结构中的作用。作为更广泛的影响，这项研究将有助于加深对影响溶解和悬浮物的沿海上升流的了解。此外，这项研究将支持一名博士后学者，并培养一名研究生和两名本科生。这一奖项反映了NSF的法定使命，并通过使用基金会的学术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 study will explore the widespread ocean phenomenon of coastal upwelling, in which nutrient-rich water is pumped toward the surface mainly by wind forcing on the sea surface. This phenomenon has pivotal influence on the appearance of fisheries in different parts of the world. The study will use mathematical models that represent idealized conditions for upwelling over a sloping continental shelf. Despite the idealizations, the models will add three-dimensionality aspects and dynamical effects caused by different water densities, i.e., by buoyancy. Results will be cast in a framework that includes the slope of the continental shelf, buoyancy effects and Earth’s rotation influence. As broader impacts, the study is expected to improve understanding on a process that affects dissolved and suspended materials near the coast. It also will train a postdoctoral scholar, a graduate student, and two undergraduate students. The proposal will explore three-dimensional pathways for coastal upwelling under vertically stratified ocean conditions. The study will use a series of idealized 3D numerical simulations, contrasting the customary 2D descriptions associated with Ekman dynamics. Simulations will be placed in a holistic framework that accounts for the interactions among wind-driven circulation, (sub)mesoscale turbulence, and boundary layer processes. Thus, simulations will address the coupling between surface and bottom boundary layers through a framework based on the slope Burger number, which compares buoyancy and Coriolis frequencies. The Burger number is expected to diagnose whether the onshore flow is along the bottom or in the interior of the water column. A particularity of this study, in addition to examining three-dimensional structures, is the assessment of the role of baroclinic instability in shaping the upwelling structure via eddy stirring along isopycnals. As broader impacts, this study will contribute advanced understanding of coastal upwelling, which affects dissolved and suspended matter. Also, the study will support one postdoctoral scholar, and train one graduate and two undergraduate students.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.