Collaborative Research: US GEOTRACES GP17-OCE: Mapping nitrous oxide sources and sinks through isotopic measurements in the Pacific Ocean

合作研究：US GEOTRACES GP17-OCE：通过太平洋同位素测量绘制一氧化二氮源和汇图

• 批准号: 2048961
• 负责人: Karen Casciotti
• 金额: $ 40.96万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-10-01 至 2024-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2048961&HistoricalAwards=false
• 关键词: Collaborative; Research; US; GEOTRACES; GP17

Nitrous oxide is a powerful greenhouse gas that is produced by microbial activity in soils and the ocean. The Pacific Ocean is an important component of oceanic nitrous oxide production and emission to the atmosphere due to its large area and pockets of low oxygen in the eastern tropical Pacific. The largest amounts of nitrous oxide observed in the global ocean occur in these pockets of low oxygen. These regions appear to impact nitrous oxide distributions throughout the Pacific Ocean, but the sources of nitrous oxide in these regions may be quite different. This work will provide a better understanding of both the natural distribution of nitrous oxide in the global ocean, as well as the mechanisms and controls on its production for future emission projections. This will be accomplished by collecting nitrous oxide isotopic measurements at different water depths from the central Pacific, where relatively little work has focused. Measurements of nitrous oxide isotopic composition is a powerful analytical tool that will help to answer these important questions about this powerful greenhouse gas. The Stanford component of this project will be carried out primarily by a PhD student, who will be trained in a variety of laboratory techniques, data analysis, and computer modeling. We will also use support from this project to increase diversity in the Geosciences by providing first-time research experiences to underrepresented minority students through Stanford’s SURGE (Summer Undergraduate Research in Geoscience and Engineering) Program. One of the project’s lead investigators, Bourbonnais, will also give a series of introductory Chemical Oceanography lectures at Benedict College, a private historically black, liberal arts college in Columbia, SC and support two undergraduate students from Benedict College through summer internships at the University of South Carolina. This project will address three main questions related to N2O cycling in the Pacific Ocean: (1) What features of N2O distribution in the central Pacific Ocean are driven primarily through mixing and circulation vs. biological processes; (2) Which biogeochemical processes control the distribution of biologically produced N2O in the central Pacific Ocean; and (3) How does the production (amount, mechanism, yield) of N2O relate to the availability of oxygen in situ? This collaborative project will be carried under the GEOTRACES program, an international effort to understand the distribution of elements in the global ocean. With the synthesis of the GEOTRACES GP17 and GP15 sections, we will have an opportunity to examine the distributions of N2O and its isotopes (an indicator of production mechanisms) relative to oxygen, trace elements, and water mass tracers. Data from this project will be made available to the public through the Biological and Chemical Oceanography-Data Management Office (www.bco-dmo.org). The data will also be compiled in GEOTRACES data products that will be freely available.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.

一氧化二氮是一种强大的温室气体，是由土壤和海洋中的微生物活性产生的。太平洋是海洋一氧化二氮在东部热带太平洋地区大面积和低氧气袋，这是海洋一氧化二氮的生产和大气排放的重要组成部分。在这些低氧的这些口袋中，在全球海洋中观察到的一氧化二氮最大。这些区域似乎会影响整个太平洋的一氧化二氮分布，但是这些区域中一氧化二氮的来源可能完全不同。这项工作将更好地了解全球海洋中一氧化二氮的自然分布，以及其生产的机制和控制，以实现未来的排放预测。这将通过从中太平洋的不同水深收集一氧化二氮同位素测量来实现，那里的工作相对较少。一氧化二氮同位素成分的测量是一种强大的分析工具，将有助于回答有关这种强大的温室气体的这些重要问题。该项目的斯坦福大学组成部分将由一名博士生进行，他们将接受各种实验室技术，数据分析和计算机建模的培训。我们还将通过该项目的支持来通过斯坦福大学的激增（地球科学和工程学）计划为代表性不足的少数群体学生提供首次研究经验，从而增加地球科学的多样性。该项目的一位主要调查人员布尔巴纳斯（Bourbonnais）还将在南卡罗来纳州哥伦比亚的一所私人历史上有历史悠久的黑人文科学院（Benedict College）提供一系列介绍化学海洋学讲座，并支持本尼迪克特学院通过南卡罗来纳大学的暑期实习生的两名本科生。该项目将解决与太平洋N2O骑自行车有关的三个主要问题：（1）中太平洋N2O分布的哪些特征是通过混合和循环与生物学过程驱动的； （2）哪些生物地球化学过程控制中太平洋中生物学产生的N2O的分布； （3）N2O的生产（数量，机制，产量）与原位氧气的可用性有何关系？该协作项目将根据Geotraces计划进行，这是一项国际努力，以了解全球海洋中要素的分布。通过GEOTRACES GP17和GP15部分的合成，我们将有机会检查相对于氧，痕量元素和水质量示踪剂的N2O及其同位素及其同位素的分布（一种生产机制的指标）。该项目的数据将通过生物和化学海洋学管理办公室（www.bco-dmo.org）提供给公众。该数据还将在GeoTraces数据产品中编辑，该数据将免费提供。该奖项反映了NSF的法定任务，并使用基金会的知识分子优点和更广泛的影响评估标准被认为是通过评估来获得的支持。