Collaborative Research: Opening the black box of oxygen deficient zone biogeochemistry through integrative tracers

合作研究：通过综合示踪剂打开缺氧区生物地球化学黑匣子

• 批准号: 2342987
• 负责人: Karen Casciotti
• 金额: $ 64.83万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-04-01 至 2027-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2342987&HistoricalAwards=false
• 关键词: Collaborative; Research; Opening; black; box

The oxygen deficient zones are regions in the ocean where dissolved oxygen disappears. These regions harbor unique ecosystems only found in waters without oxygen, and they are important for Earth’s climate. Specifically, the production of nitrogen gas by two microbial processes, anammox and denitrification can control how productive the oceans are. Yet how much each process shapes ocean chemistry within these areas remains unknown. This project aims to study the oxygen deficient waters of the eastern tropical North Pacific ocean to better understand the mechanisms shaping marine nitrogen and carbon chemistry. Through this work, the project will train undergraduate and graduate students at three universities. The project aims to broaden participation in and understanding of ocean sciences by developing public videos about the methods used and the science behind the project. The investigators will conduct a research cruise in the eastern tropical North Pacific ocean, the largest oxygen deficient zone. They will measure many nutrients including inorganic carbon and nitrogen and natural abundance stable isotopes of nitrogen compounds. They will use these patterns to establish how the major reactions work together to control nitrogen cycling and gaseous nitrogen production. In addition, a high-resolution model of the ocean will reveal the influence of ocean mixing, set the timescales for reactions, and enable synthesis of the measurements into a global context. The work will determine how the input of oxygen through mixing controls chemistry, and it will distinguish between the processes restricted to the permanently anoxic core vs. those that tolerate (or are enhanced by) occasional oxygenation. Overall, the project will provide new information about nitrogen cycling pathways (anammox, denitrification, and nitrite oxidation) across the region and link the resulting isotopic signals to the global nitrogen budget.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

缺氧区是海洋中溶解氧消失的区域。这些地区拥有独特的生态系统，只有在没有氧气的水域才能找到，它们对地球的气候很重要。具体来说，通过厌氧氨氧化和反硝化两种微生物过程产生的氮气可以控制海洋的生产力。然而，每个过程在多大程度上影响了这些地区的海洋化学仍然未知。该项目旨在研究北太平洋东部热带缺氧水域，以更好地了解海洋氮和碳化学的形成机制。通过这项工作，该项目将在三所大学培养本科生和研究生。该项目旨在通过制作有关所使用的方法和项目背后的科学的公开视频，扩大对海洋科学的参与和了解。调查人员将在热带北太平洋东部进行一次研究巡航，这是最大的缺氧区。他们将测量许多营养物质，包括无机碳和氮，以及氮化合物的天然丰度稳定同位素。他们将利用这些模式来确定主要反应如何协同工作以控制氮循环和气态氮的产生。此外，一个高分辨率的海洋模型将揭示海洋混合的影响，设定反应的时间尺度，并能够将测量结果综合到全球范围内。这项工作将决定通过混合输入的氧气如何控制化学反应，并将区分限制在永久缺氧核心的过程与那些容忍（或通过偶尔的氧化而增强）的过程。总体而言，该项目将提供有关该地区氮循环途径（厌氧氨氧化、反硝化和亚硝酸盐氧化）的新信息，并将由此产生的同位素信号与全球氮收支联系起来。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。