Collaborative Research: Productivity, Biogeochemical Transformations and Cross-margin Transport in an Eastern Boundary Buoyant Plume Region

P.I. Hickey，Barbara（UW）项目摘要本提案侧重于高产的东部边界哥伦比亚河羽。这个羽流足够大，具有区域重要性，但又足够小，可以确定影响河流羽流的主要过程，并便于与羽流以外的区域进行速率比较。拟议的研究将整合附近风力驱动的CoOP研究的结果，以及附近的GLOBEC和ECOHAB项目，以提供有关地球化学过程速率变化的确切新信息。独特的分层、浑浊度、混合环境和营养物质。此外，由于哥伦比亚河提供了没有显着的terrigneous硝酸盐的羽在生长季节，这项研究允许羽特有的过程被隔离，因此过程的结果可以直接应用到其他羽。结果也可以与更多的富营养化，浮力影响的沿海地区。拟议的研究将解决三个假设：-在上升流的浮游植物的羽内的增长率超过附近地区以外的羽被相同的上升流宏量营养素。- 羽流增强了浮游生物和营养物质的跨界运输。- 羽特有的营养物质（Fe和SiO 4）改变并提高了附近大陆架的生产力。拟议的战略是比较生产率内的羽流和羽流外，在更富有成效的大陆架北部的河口（华盛顿）和生产力较低的大陆架南部（俄勒冈州）。这项研究的结果解决了一个重要的问题，为什么一个大陆架较弱的上升流风是更高的生产力比大陆架强风。

P.I. Hickey, Barbara (UW)Project Summary This proposal focuses on the highly productive Eastern Boundary Columbia river plume. This plume is sufficiently large to be of regional importance, yet small enough to allow determination of dominant processes affecting river plumes, and to facilitate rate comparisons with regions outside the plume The proposed study will integrate results from the nearby wind-driven CoOP study, as well as with those from nearby GLOBEC and ECOHAB projects to provide definitive new information on alteration of rates of biogeochemical processes by the unique stratification, turbidity, mixing environment and nutrients of a river plume. Moreover, because the Columbia River provides no significant terrigneous nitrate to the plume in the growing season, this study allows plume-endemic processes to be isolated and hence process results can be directly applied to other plumes. Results can also be contrasted with more eutrophic, buoyancy-influenced coastal areas.The proposed study will address three hypotheses: - During upwelling the growth rate of phytoplankton within the plume exceeds that in nearby areas outside the plume being fueled by the same upwelling macronutrients. - The plume enhances cross-margin transport of plankton and nutrients. - Plume-specific nutrients (Fe and SiO4) alter and enhance productivity on nearby shelves. The proposed strategy is to compare production rates within the plume and outside the plume, on the more productive shelf to the north of the river mouth (Washington) and the less productive shelf to the south (Oregon). Results from this study address important question as to why a shelf with weaker upwelling winds is more highly productive than a shelf with stronger winds.