Toward a more complete understanding of coastal upwelling dynamics

这项研究将探索沿海上升流这一广泛存在的海洋现象，在这种现象中，富含营养的水主要是通过海面上的风强迫被泵向海面。这一现象对世界不同地区的渔业形态有着关键的影响。这项研究将使用数学模型来代表倾斜大陆架上升流的理想条件。尽管理想化了，但模型将增加三维方面和由不同水密度（即浮力）引起的动力学效应。研究结果将纳入一个框架，其中包括大陆架的坡度、浮力效应和地球自转的影响。从更广泛的影响来看，这项研究有望提高人们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沿海上升流的三维路径。该研究将使用一系列理想化的3D数值模拟，对比与Ekman动力学相关的传统2D描述。模拟将被放置在一个整体框架中，以解释风驱动环流、（次）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汉堡数的框架来解决表面和底部边界层之间的耦合，该框架比较浮力和科里奥利频率。伯格数被期望用来诊断岸上的流动是沿着底部还是在水柱的内部。除了研究三维结构外，本研究的一个特点是评估斜压不稳定性在通过沿等压线的涡流搅拌形成上升流结构中的作用。就更广泛的影响而言，本研究将有助于深入了解影响溶解和悬浮物的沿海上升流。资助博士后1人，培养研究生1人，本科生2人。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识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.