Hydrogen production and nitrogen fixation in the North Pacific Subtropical Gyre

北太平洋副热带环流的氢气生产和固氮

• 批准号: 1153656
• 负责人: David Karl
• 金额: $ 28.14万
• 依托单位: University of Hawaii
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-04-01 至 2016-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1153656&HistoricalAwards=false
• 关键词: Hydrogen; production; nitrogen; fixation; North

In this project, researchers at the University of Hawaii a Manoa will conduct a series of field and laboratory studies to develop a quantitative understanding of dissolved hydrogen (H2) cycling in the oligotrophic North Pacific Ocean. Dissolved H2 concentrations in the surface ocean typically range from 1-3 nM which represents 300-900% supersaturation relative to atmospheric concentrations. This persistent supersaturation of dissolved H2 in the surface waters of subtropical and tropical oceans makes the oceans a source of atmospheric H2 and compiled budgets of global H2 sources estimate marine emissions from 3 to 6 Tg H2 yr-1. The broad objectives of the research are: (1) to quantify the linkages and stoichiometry between H2 production and N2 fixation in surface seawater of the open ocean, and (2) to determine the factors that drive this relationship including the microbial community composition and the influence of light intensity. The field research will be conducted over a two-year period at Station ALOHA and will complement the ongoing Hawaii Ocean Time-series (HOT) program. Broader Impacts: Quantifying the H2 cycling in surface waters of the upper water column will constrain existing estimates of global marine H2 emissions. Furthermore, an improved understanding of H2 cycling will help predict potential effects of increasing anthropogenic emissions of H2 increase or a climate-driven change in the community structure of marine diazotrophs. These results will be valuable to microbial ecologists, biogeochemists, and climate change scientists. All resulting oceanographic and laboratory datasets will be archived in the online HOT and Center for Microbial Oceanography: Research and Education (C-MORE) data centers and made publicly available. At least one undergraduate student will be hosted through the C-MORE scholars program which particularly targets Native Hawaiians and Pacific Islanders majoring in an ocean or earth science-related field.

在该项目中，夏威夷大学A Manoa的研究人员将进行一系列的现场研究，以对北部太平洋中溶解氢（H2）循环的循环循环进行定量理解。地表海中溶解的H2浓度通常在1-3 nm范围内，相对于大气浓度代表300-900％过饱和。在亚热带和热带海洋的地表水域中溶解的H2的这种持续过饱和使海洋成为大气H2的来源，并编制了全球H2来源的预算，估计海洋排放量的3到6 Tg H2 YR-1。 该研究的广泛目标是：（1）量化公开海洋表面海水中H2生产和N2固定之间的联系和化学计量，以及（2）确定驱动这种关系的因素，包括微生物群落组成和光强度的影响。 现场研究将在两年的Aloha进行，并将补充正在进行的夏威夷海洋时间序列（HOT）计划。更广泛的影响：量化上水柱的地表水中的H2循环将限制全球海洋H2排放的现有估计值。此外，对H2循环的改进理解将有助于预测增加H2增加的人为发射的潜在影响，或者在海洋重氮营养的社区结构中变化或气候驱动的变化。这些结果对于微生物生态学家，生物地球化学家和气候变化科学家来说将是有价值的。所有由此产生的海洋学和实验室数据集将在在线热和微生物海洋学中心存档：研究与教育（C-MORE）数据中心，并公开可用。至少一名本科生将通过C-More学者计划主持，该计划特别针对与海洋或地球有关的领域主修的夏威夷原住民和太平洋岛民。