GLOBEC-NEP: Topographic Control of Mesoscale Variability in the Gulf of Alaska

本项目研究阿拉斯加湾大陆架的物理和生物分布和过程及其对幼鲑鱼补充的影响。该项目的首要主题是沿陆架和跨陆架的中尺度结构是由于海流的水深控制。与此相关的物理海洋学特征是阿拉斯加海岸流，它在苏厄德涡旋和苏厄德反涡旋中的离岸漂移，大陆架断裂锋，斜坡涡旋和曲流以及深流。这些特征影响着深水浮游动物的运输和分布，这些浮游动物被认为是幼鲑鱼的重要食物来源，并可能决定它们的生存。一种波浪状的水下拖曳工具（SeaSoar）被用于连续绘制盐度、温度、深度和生物光学特性。上述表面样品、营养物和叶绿素荧光正在使用类似的传感器连续测量。pi使用声学多普勒电流分析器（ADCP）来测量150米深度的沿航迹和交叉航迹流速。监测站将用盐度、温度、营养成分和浮游植物的现场样本校准上述数据。这项研究的更广泛影响包括培训两名多学科海洋学博士研究生，以及更好地了解海洋学对阿拉斯加湾鲑鱼变异的影响。

This project addresses studies of the physical and biological distributions and processes and their effect on juvenile salmon recruitment on the Gulf of Alaska shelf. The overriding theme of the project is that along-shelf and cross-shelf mesoscale structures are due to bathymetric control of the currents. Physical oceanographic characteristics associated with this are the Alaska Coastal Current, its offshore excursions in the Seward Eddy and Seward Counter Eddy, the shelfbreak front, slope eddies and meanders and the deep flow. These features affect the transport and distribution of deep-water zooplankton that are alleged to be an important food source for juvenile salmon and may determine their survival. An undulating, underwater, towed vehicle (SeaSoar) is being used to continuously map salinity, temperature, depth and bio-optical properties. Surface samples of the above, nutrients, and chlorophyll fluorescence are being measured continuously using similar sensors. The PIs are using an Acoustic Doppler Current Profiler (ADCP) to measure along- and cross-track current velocities to 150 m depth. The PIs will calibrate the above with on-station samples of salinity, temperature, nutrients and phytoplankton. The broader impacts of this study include training of two PhD students in multidisciplinary oceanography and a better understanding of the effects of oceanographic effects on salmon variability in the Gulf of Alaska.