Collaborative Research: Coastal Ocean Advances in Shelf Transport (COAST): Iron Input and Wind-driven Circulation along the Oregon Coast

俄勒冈州立大学、北卡罗来纳大学和哥伦比亚大学的van GeenInvestigers将合作进行一项为期五年的密集研究，将一套独特的观测工具与海洋和大气模型结合起来，研究俄勒冈沿海海洋的环流、生物和化学。该项目是由沿海海洋过程(COOP)计划赞助的，是对东北太平洋风驱动过程研究机会的宣布的回应。俄勒冈州大陆架上的研究区域在夏季和冬季都对风的强迫做出了强烈的反应，夏季的平均风有利于上升流，冬季的平均风有利于下行流。将通过进行实地实验、协调海洋环流/生态系统和大气模拟来处理与风力驱动系统中跨陆架运输过程有关的一系列科学假设。这些假设是：(1)上升和下降的急流和锋面的存在局部地改变了陆架上、下边界层和内部的跨陆架环流；(2)近岸地形的变化决定了二维和三维跨陆架输送过程的相对重要性；(3)上升和下降过程中陆架上的湍流模式受到锋面和急流的影响，湍流水平可以达到足以影响中尺度环流的强度；(4)陆架上初级生产的大小和分布及其随后向近岸的输送完全受上升流几何形状的控制；(5)湍流混合的沿岸变化控制着初级生产力的大小和分布；以及(6)下降锋的存在意味着跨陆架运输的减少，使得浮游植物和浮游动物的营养物质、痕量金属和种子储备积累在中陆架到内陆架，从而使系统在上升潮开始时有强烈的生物反应。为了解决这些假设，将在两个区域进行密集的观测：一个在地形相对简单的区域，一个在地形陡峭的区域。将使用船舶、一架仪表式飞机、一套系泊设备和一台陆基沿海雷达进行高分辨率采样，以绘制高空间分辨率的地表流图。将使用一个高分辨率的三维大陆架环流和耦合生态系统海洋模式，通过对观测结果的动态综合和相关过程研究，直接支持实地实验。中尺度大气模拟工作将为海洋模型和解释海洋观测提供在空间和时间上连续的表面强迫估计。这些测量汇集了一套独特的观测工具，以前没有同时应用于海岸动力学研究。与海洋环流/生态系统和大气模拟相协调，拟议的工作将极大地促进我们对风力驱动的大陆架上跨陆架运输过程的理解。

9907953van GeenInvestigators at Oregon State University, University of North Carolina, and Columbia University will collaborate on an intensive five-year study to combine a unique set of observational tools and ocean and atmosphere models to investigate the circulation, biology, and chemistry of the Oregon coastal ocean. This project is under the auspices of the Coastal Ocean Processes (CoOP) Program and is in response to an Announcement of Opportunity for Wind-Driven Process Studies in the Northeast Pacific. The area to be studied on the Oregon shelf responds strongly to wind forcing during both summer, when mean winds favor upwelling, and winter, when mean winds favor downwelling. A set of scientific hypotheses related to cross-shelf transport processes in a wind-driven system will be addressed by conducting field experiments together with coordinated ocean circulation/ ecosystem and atmospheric modeling. The hypotheses are: (1) the presence of upwelling and downwelling jets and fronts locally alters cross-shelf circulation in the surface and bottom boundary layers and in the interior; (2) alongshore topographic variations dictate the relative importance of two-dimensional versus three-dimensional cross-shelf transport processes; (3) patterns of turbulence on the shelf during upwelling and downwelling are influenced by fronts and jets, and the levels of turbulence can reach sufficient intensity to influence the mesoscale circulation; (4) the magnitude and distribution of primary production on the shelf and its subsequent transport offshore is controlled solely by the geometry of upwelling; (5) alongshore variations in turbulent mixing control the magnitude and distribution of primary production; and (6) the reduced cross-shelf transport implied by the presence of a downwelling front allows nutrients, trace metals and seed stocks of phytoplankton and zooplankton to accumulate in the mid- to inner shelf, thus priming the system for a strong biological response at the outset of upwelling.To address the hypotheses, intensive observations will be made in two regions: one in a region of relatively simple topography and one in a region of abrupt topography. High-resolution sampling will be conducted using ships, an instrumented aircraft, a set of moorings, and a land-based coastal radar to make high -spatial resolution surface current maps. A high-resolution, three-dimensional shelf circulation and coupled ecosystem ocean model will be used in direct support of the field experiments by contributing to the dynamical synthesis of the observations and for relevant process studies. A mesoscale atmospheric modeling effort will provide estimates of surface forcing, continuous in space and time, for the ocean model and for interpretation of the oceanic observations.These measurements bring together a unique set of observational tools not previously applied simultaneously to the study of coastal dynamics. Coordinated with ocean circulation/ecosystem and atmospheric modeling, the proposed effort will significantly advance our understanding of cross-shelf transport processes on wind-driven continental shelves.