Collaborative Research: Use of Triple Oxygen Isotopes and O2/Ar to constrain Net/Gross Oxygen Production during upwelling and non-upwelling periods in a Coastal Setting

合作研究：使用三重氧同位素和 O2/Ar 来限制沿海地区上升流和非上升流期间的净/总氧气产量

• 批准号: 1260692
• 负责人: Douglas Hammond
• 金额: $ 42.12万
• 依托单位: University of Southern California
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-04-15 至 2017-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1260692&HistoricalAwards=false
• 关键词: Collaborative; Research; Use; Triple; Oxygen

The marine biological pump is one of the primary pathways via which anthropogenic carbon dioxide may be sequestered from the atmosphere and exported to the deep ocean as organic carbon. While the link between nutrient supply and high primary productivity in upwelling regions is well established, factors controlling the organic carbon export efficiency of upwelling ecosystems are not well known. Scientists from the University of Southern California and Pomona College plan to determine the factors that control the rates and magnitudes of two components of biological production, Net Community Production (NCP) and Gross Primary Production (GPP), as well as particulate organic carbon export efficiency, at the San Pedro Ocean Time Series, a coastal site in the California Borderland during periods of minimal and high upwelling velocity over a 2-year span. At this site, past and ongoing observations of hydrography and carbon rain will provide an historical context for interpreting results and mechanisms at work. Rates of NCP and GPP will be quantified at different upwelling intensity, using dissolved oxygen to argon (O2/Ar) ratios and the oxygen triple isotope composition of dissolved oxygen (O2). The export of organic carbon will be established using 234Th (thorium) profiles in the water column, coupled with floating sediment trap deployments, and the development of a carbon isotope balance for the water column. Upwelling will be characterized using non-steady state budgets for atmospheric 7Be (beryllium) input and its depth-integrated decay, as well as estimating rates based on remote measurements of wind stress curl and budgets for dissolved inorganic carbon and silicon. Application of the O2/Ar ratio and the oxygen triple isotope approach will require depth-integrated profiles of these tracers to evaluate the impact of upwelling on mixed layer inputs and use of non-steady state models during seasonal transitions in upwelling. The comprehensive data set to be obtained should provide insights into the organic carbon export efficiency under variable upwelling regimes and help to relate the satellite-based measurements of chlorophyll to the organic carbon export of these highly productive ecosystems.Broader Impacts: One graduate and one undergraduate student from the University of Southern California and two undergraduate students from Pomona College would be supported and trained as part of this project.

海洋生物泵是可以从大气中隔离人为二氧化碳并以有机碳出口到深海的主要途径之一。 虽然良好的养分供应与上升区域的高主要生产率之间的联系已经建立，但控制上升生态系统的有机碳出口效率的因素并不众所周知。 南加州大学和波莫纳学院的科学家计划确定控制生物生产的速度和大小的因素，净社区生产（NCP）和主要产量（GPP）（GPP）以及有机碳出口效率，以及在加利福尼亚州沿海地区的沿海地区，在最小范围和高高的高处vel vel vel vel的沿海地区，有机碳出口效率以及颗粒物有机碳的出口效率。 在这个地点，过去和正在进行的水文和碳降雨的观察将为解释工作中的结果和机制提供历史背景。 NCP和GPP的速率将在不同的上升强度下使用溶解的氧气（O2/AR）比和溶解氧的氧三同位素组成（O2）来量化。 有机碳的出口将使用水柱中的第234（thor）轮廓建立，再加上浮动沉积物陷阱的部署，并开发了水柱的碳同位素平衡。 上升的特征将使用非稳态的状态预算，用于大气7BE（铍）输入及其深度融合的衰减，以及基于风应力卷曲的远程测量和溶解的无机碳和硅的预算进行估算。 O2/AR比的应用和氧三同位素方法的应用将需要这些示踪剂的深度集成曲线，以评估上升对混合层输入的影响，并在上升期间季节性过渡期间使用非稳态的状态模型。 在可变上升方案下，应获得的全面数据应提供有关有机碳出口效率的见解，并有助于将基于卫星的叶绿素的测量与这些高生产力生态系统的有机碳出口相关联。从南加州大学和两名培训学院培养了一名毕业生，一位毕业生和一名毕业生。