Collaborative Research: Applying O2/Ar, DELTA17O and 222Rn methodologies to constrain organic carbon productivity in the upper ocean of the ETSP

合作研究：应用 O2/Ar、DELTA17O 和 222Rn 方法来限制 ETSP 上层海洋的有机碳生产力

• 批准号: 0961207
• 负责人: William Berelson
• 金额: $ 30.2万
• 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: 2010
• 资助国家: 美国
• 起止时间: 2010-02-15 至 2013-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0961207&HistoricalAwards=false
• 关键词: Collaborative; Research; Applying; O2; Ar

Recently the National Science Foundation funded a field campaign to study the occurrence of nitrogen fixation in the eastern tropical South Pacific (ESTP-10°S-20°S, 80°W-110°W) and determine its contribution as a source of new nitrogen to primary production in the region. The proposed cruise tracks cover a wide range in primary productivity, from some of the most productive to least productive marine waters in the world. Two scientists from the University of Southern California in collaboration with a researcher from the University of California, Los Angeles will participate in the cruises to quantify the contribution of nitrogen fixation to primary and export production rates. To attain their goal, the researchers would determine Net Community Production and Gross Photosynthetic Production (NCP and GPP) by measuring biological O2 supersaturation and 17O excess of oxygen dissolved in the upper ocean. Oxygen supersaturation from biological processes can be determined from measuring O2/Ar ratios of near surface waters, which effectively removes the effect of supersaturation produced by bubble injection and other physical processes. The 17O excess permits surface water oxygen that has been produced by photosynthesis in situ to be distinguished from oxygen from the atmosphere. In addition, 222Rn profiles in the upper water column would also be obtained and used to assess the rate of air-sea gas exchange and eddy diffusivity across the thermocline. A system to measure near-surface radon while underway is also planned and should ascertain spatial/temporal variability in gas exchange and help identify recently upwelled or downwelled water masses. Results for the O2/Ar and delta 17O methodologies, coupled with areal mapping of radon deficiencies will yield an excellent data base for estimation of carbon export within the ETSP.In terms of broader impacts, the research may lead to reduced uncertainties in the gas exchange rates which could improve the precision of productivity measurements. This project represents a collaborative effort between two academic institutions in the Los Angeles area. One postdoc and two undergraduate students from the University of Southern California will be supported and trained as part of the project.

最近，国家科学基金会资助了一项现场运动，以研究东部热带南太平洋（ESTP-10°S-20°S，80°W-1110°W）的氮固定发生，并确定其作为该地区初级生产的新氮的贡献。拟议的巡航轨道涵盖了初级生产的广泛范围，从世界上最有生产力至最低生产力的海水。南加州大学与加州大学洛杉矶分校的一名研究人员合作的两名科学家将参加巡航，以量化氮固定对初级和出口生产率的贡献。为了实现他们的目标，研究人员将通过测量生物学O2过饱和度和17O超过氧气溶于上海洋中的氧净生产和光合生产（NCP和GPP）。可以通过测量近地表水的O2/AR比确定生物过程中的氧过饱和，从而有效消除了气泡注入和其他物理过程产生的过饱和的影响。 17o超过光合作用原位产生的地表水氧，以与大气中的氧气区分开。此外，还将获得上水柱中的22222rn剖面，并用于评估整个热跃层的气海气交换和涡流难度的速率。还计划了一个测量近地面rad的系统，还应确定气体交换中的空间/时间变异性，并有助于识别最近上升或下降的水质量。 O2/AR和DELTA 17O方法的结果，再加上ra不足的面积映射将产生出色的数据库，以估算ETSP内的碳导出。在更广泛的影响方面，该研究可能导致气体汇率不确定性降低，从而可以提高生产率测量的精确度。该项目代表了洛杉矶地区的两个学术机构之间的合作努力。作为该项目的一部分，将为一名来自南加州大学的博士后和两名本科生提供支持和培训。