Impact of the Keweenaw Current on Cross-Margin Transport in Lake Superior Physical Processes, Chemical Gradients, and Biological Communities

基韦诺洋流对苏必利尔湖物理过程、化学梯度和生物群落跨界输运的影响

• 批准号: 9712869
• 负责人: Changsheng Chen
• 金额: $ 67.56万
• 依托单位: University of Georgia Research Foundation Inc
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-09-15 至 2001-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9712869&HistoricalAwards=false
• 关键词: Impact; Keweenaw; Current; Cross; Margin

9712869 Chen Research will be undertaken in response to an Announcement of Opportunity (NSF 97-38) for Coastal Studies in the Great Lakes. This is a collaborative research project involving eleven investigators from five academic research institutions. The research is being conducted under the auspices of the NSF Coastal Ocean Processes (CoOP) program and the NOAA Coastal Ocean Program. This collaborative, interdisciplinary 5-year research program will entail an integrated program of field and laboratory studies and mathematical modeling to quantify the role of coastal currents and thermal fronts in mediating cross-margin transport in Lake Superior. The western shore of Lake Superior's Keweenaw Peninsula exhibits a dramatic coastal jet known as the Keweenaw Current. A strong, shore-parallel density front, the thermal bar, also is characteristic of this region and persists long into the summer. The goal of the proposed work is to determine the physical, chemical, and biological effects that arise from the intense physical forcing on this system, and specifically, to elucidate how these effects interact temporally and spatially to define distinct nearshore and offshore environments in Lake Superior. This project represents the first effort to model coupled physical, chemical, and biological processes in the coastal zone of Lake Superior where both vertical and horizontal thermal structure and transport processes are important. The research team is divided into three subgroups: Physical Processes, Chemical Gradients, and Biological Communities. The Physical Processes group will examine the relative importance of all forcing factors (e.g., wind-driven variability, baroclinic instability) that govern cross margin transport using in situ observations, numerical modeling, and satellite observations. The Chemical Gradients group will characterize nearshore-offshore differences in distributions of chemical species, evaluate chemical tracers of wat er and sediment movement, and investigate differences (inshore vs. offshore) in chemical cycles induced by the current. The Biological Communities group will determine how gradients in primary production, trophic structure, and rates of material transformation develop. All three groups will interact closely throughout the project to obtain and share complementary data sets and to derive a coupled physical/chemical/biological model of the system. The detailed, process-level understanding achieved by this project will advance our quantitative understanding of the processes that regulate the transport, transformation and fate of biologically, chemically and geologically important matter in coastal regions and provide a firm basis for future management decisions on how best to preserve the pristine nature of Lake Superior. This particular project will contribute to the activities of the Physical Processes subgroup that will measure currents, thermal, and density structure in order to define the spatial and temporal extent of the Keweenaw Current and thermal bar. This research will also develop and test a coupled biological-physical model for the Keweenaw Current environment.

9712869 Chen 研究将根据五大湖沿海研究机会公告（NSF 97-38）进行。 这是一个合作研究项目，涉及来自五个学术研究机构的十一名研究人员。 该研究是在 NSF 沿海海洋过程 (CoOP) 计划和 NOAA 沿海海洋计划的支持下进行的。 这项为期 5 年的跨学科合作研究计划将需要一个实地和实验室研究以及数学建模的综合计划，以量化沿海流和热锋在调节苏必利尔湖跨边缘运输中的作用。 苏必利尔湖基威诺半岛的西岸有一股引人注目的沿海急流，称为基威诺洋流。 强烈的、与海岸平行的密度锋，即热坝，也是该地区的特征，并持续到夏季。拟议工作的目标是确定该系统上强烈的物理强迫所产生的物理、化学和生物效应，特别是阐明这些效应如何在时间和空间上相互作用，以定义苏必利尔湖独特的近岸和近海环境。 该项目是对苏必利尔湖沿岸地区耦合物理、化学和生物过程进行建模的首次尝试，该地区的垂直和水平热结构和传输过程都很重要。 研究小组分为三个小组：物理过程、化学梯度和生物群落。 物理过程小组将利用现场观测、数值模拟和卫星观测来研究控制跨缘输运的所有强迫因素（例如，风驱动的变异性、斜压不稳定性）的相对重要性。 化学梯度小组将表征近岸和近海化学物质分布的差异，评估水和沉积物运动的化学示踪剂，并研究水流引起的化学循环的差异（近岸与近海）。 生物群落小组将确定初级生产、营养结构和物质转化率的梯度如何发展。所有三个小组将在整个项目中密切互动，以获取和共享互补的数据集，并得出系统的耦合物理/化学/生物模型。 该项目所实现的详细、过程层面的理解将促进我们对调节沿海地区生物、化学和地质重要物质的运输、转化和归宿的过程的定量理解，并为未来的管理决策提供坚实的基础，以了解如何最好地处理这些物质。保护苏必利尔湖的原始自然。 这个特定项目将有助于物理过程小组的活动，该小组将测量电流、热量和密度结构，以便定义基威诺电流和热棒的空间和时间范围。这项研究还将开发和测试基韦诺海流环境的耦合生物物理模型。