Physical Control of Carbon Export in the Subarctic Pacific

亚北极太平洋碳输出的物理控制

• 批准号: 1129090
• 负责人: Charles Eriksen
• 金额: $ 32.36万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-15 至 2014-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1129090&HistoricalAwards=false
• 关键词: Physical; Control; Carbon; Export; Subarctic

Intellectual Merit: One of the largest outstanding and ongoing research problems in the physical and biogeochemical oceanographic community concerns the fate of organic carbon generated from primary production in the surface ocean. Though carbon export exerts a profound control on CO2 concentrations in the world?s atmosphere, in-situ measurements of production rates are not fully reconciled with those inferred from the global annual average, and the spectrum of variability of carbon export in a variety of oceanic environments has yet to be fully determined. A popular method for evaluating ocean metabolism is the formulation of an oxygen mass balance, in which an oxygen budget is constructed in the mixed layer or euphotic zone, the effects of physical processes are removed, and the residual oxygen production is stoichiometrically related to the export of carbon to depth. While ship-based oxygen mass balance studies are hindered largely by expense and the availability of resources, recent efforts using remote measurement of oxygen from moored sensors display considerable potential for cost-effective and geographically widespread diagnostics of the biological pump. These techniques have been expanded to mobile autonomous platforms such as profiling Argo floats and ocean gliders, which offer an enhanced, highly-resolved vertical and horizontal picture of major physical processes controlling primary production.Continuing the evolution of studies of net biological oxygen production from autonomous platforms, the project will apply a comprehensive physical and oxygen mass balance assessment to a remote-sensing time series of unprecedented duration and resolution: the University of Washington Seaglider Ocean Station P time series in the southern Gulf of Alaska. Three separate Seaglider deployments orbited the well-instrumented National Oceanic and Atmospheric administration Pacific Marine Environmental Laboratory (NOAA/PMEL) Station P mooring from June 2008 to January 2010, collecting detailed vertical and horizontal profiles of basic physical properties, bio-optical variables, and dissolved oxygen. During extended portions of this time, the Station P mooring observed atmospheric variables and corresponding physical parameters within the near surface ocean; taken together these datasets represent a powerful tool for adding to the established picture of physical variability and net oxygen production in the central subarctic Pacific Ocean. In the course of our proposed analysis, we hope to: 1) better constrain horizontal advection, vertical advection, and diapycnal mixing processes, as they apply to the budget of an active tracer; 2) obtain a robust estimate of net oxygen production in the mixed layer during the course of the time series; 3) evaluate respiration (oxygen consumption) below the mixed layer and above the permanent halocline; and 4) estimate the dependence with depth of respiration below the pycnocline. Broader Impacts: This project will expand the knowledge base of the physical dynamics controlling the biological pump in the Gulf of Alaska as well as add to the length of the time series which has been analyzed in a carbon export context. A better understanding of advection in the surface layer would allow comparison to previous residual estimates of this term and its relative importance at each phase of the seasonal cycle. Exploring the dependence in time and depth of diapycnal diffusivity would improve and clarify our knowledge of its role in vertical transport of oxygen at Station P. Additionally, analysis of a combined moored and autonomous vehicle time series should provide a foundation of techniques to be used in similar future deployments in difficult-to-observe regions of the world ocean.

知识分子的优点：物理和生物地球化学海洋学社区中最大和正在进行的研究问题之一，涉及地面海洋初级生产产生的有机碳的命运。尽管碳出口对世界大气中的二氧化碳浓度产生了深远的控制，但生产率的原位测量与从全球年度平均平均水平推断的二氧化碳浓度并未完全核对，并且在各种海洋环境中碳出口的可变性范围尚未得到充分确定。评估海洋代谢的一种流行方法是氧质量平衡的制定，其中氧预算在混合层或爵士区域中构建，去除物理过程的影响，并且残留的氧气产生与碳的导出到深度之间。尽管基于船舶的氧气平衡研究在很大程度上受到了费用和资源的可用性的影响，但最近使用系泊传感器对氧气进行远程测量的努力表现出了巨大的潜力，这些潜力对于生物泵的成本效益和地理上广泛的诊断。这些技术已扩展到移动自主平台，例如分析Argo浮动和海洋滑翔机，这些平台提供了控制基本生产的主要物理过程的增强，高度解决的垂直和水平图片，从而将净生物氧气生产的研究进化为自主氧的净生产，该项目将采用全面的物理和氧气评估，以解决远程和氧气平衡的范围：远程评估的远程评估：该计划的远程和氧气平衡的范围：华盛顿大学海格利德大学海洋站P时间系列在阿拉斯加南部海湾。从2008年6月至2010年1月，三个独立的Seaglider部署绕过盛有启发性的国家海洋和大气管理局Pacific Pacific Marine环境实验室（NOAA/PMEL）电台P系泊机，收集了基本物理特性的详细垂直和水平概况，生物光变量和溶解的牛根。在这段时间的延长部分中，台站泊式观察到大气变量和近地面海洋内的相应物理参数。综上所述，这些数据集代表了一种强大的工具，可添加中部亚亚亚亚亚基元中既定的物理变异性和净氧产生图。在我们提出的分析过程中，我们希望：1）更好地限制水平对流，垂直对流和iapynal混合过程，因为它们适用于主动示踪剂的预算； 2）在时间序列的过程中，获得混合层中净氧产生的可靠估计； 3）评估混合层以下和永久卤素之上的呼吸（消耗氧）； 4）估计呼吸深度以下的依赖性。更广泛的影响：该项目将扩大控制阿拉斯加海湾生物泵的物理动力学的知识库，并增加了时间序列的长度，该时间序列已在碳出口环境中进行了分析。更好地理解表面层中的对流，将使对该术语的先前剩余估计及其在季节周期的每个阶段的相对重要性进行比较。探索二比纳扩散率的时间和深度的依赖性将改善并阐明我们对站点氧气中氧气中的作用的了解。此外，对合并的系泊和自动驾驶汽车时间序列的分析应为在世界海洋地区的困难攻击区域中的类似部署中使用的技术提供基础。