Collaborative Research: US GEOTRACES PMT: Investigating geochemical tracers of the Pacific nitrogen cycle and budget

合作研究：US GEOTRACES PMT：研究太平洋氮循环和预算的地球化学示踪剂

• 批准号: 1736652
• 负责人: Daniel Sigman
• 金额: $ 36.14万
• 依托单位: Princeton University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1736652&HistoricalAwards=false
• 关键词: Collaborative; Research; US; GEOTRACES; PMT

Nitrate is an important nutrient that marine plants and algae need for growth. It is abundant in deep ocean waters, but scarce in most sunlit surface waters. The purpose of this project is to better understand what controls the availability of nitrate in the deep ocean and its delivery to surface waters. Researchers from Stanford University, Princeton University, and Brown University will analyze the stable isotopes of seawater nitrate collected between Alaska and Tahiti in the Pacific Ocean. The data will provide information about the supply of nitrate to a large section of the Pacific Ocean and allow informed decisions on past and future changes in marine photosynthesis. This collaborative project will be carried under the GEOTRACES program, an international effort to understand the distribution of elements in the global ocean. This study will include undergraduate, graduate, and postdoctoral researchers at all three academic instititutions. The investigators will develop a 1-day workshop for the Teachers as Scholars program, for middle and high school teachers at Princeton University. The workshop will focus on accessing and visualizing ocean data sets and other content available on the internet for project-based learning in the classroom. Investigators will also participate in teacher workshops offered each summer at Stanford University. 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.The isotopic composition of nitrate in the ocean interior records biogeochemical and physical processes on the time scales of years, decades, centuries, and millennia, with the shallow subsurface and deep ocean recording shorter and longer time scales, respectively. These are meaningful time scales in the efforts to (1) understand the feedbacks that structure the biogeochemistry of N in the ocean, ocean productivity, and the global carbon cycle, (2) reconstruct past changes in ocean biogeochemistry and carbon cycling, and (3) perhaps predict future changes. This proposal seeks to analyze the nitrate isotopes during the upcoming US GEOTRACES Pacific Meridional Transect (GP15) between Alaska and Tahiti. Nitrate isotopes provide critical constraints on the ocean N cycle and budget, especially in the Pacific Ocean where a variety of processes affect the distribution of nitrate and its supply to surface waters. This largely meridional section of nitrate isotope data will be broadly useful as part of the growing nitrate isotope dataset for the global ocean and for comparison to the many complementary geochemical data sets that will be generated as part of this GEOTRACES effort. In addition, nitrate isotopes in aerosols will be measured to support interpretations of nitrate isotopes in surface waters along the section. The proposed measurements will contribute to the investigation of three overarching questions: 1) What are the similarities and differences in N biogeochemistry among the different nutrient-rich regions in the Pacific basin: the Southern Ocean, equatorial Pacific, and subarctic North Pacific, and how do they affect nitrate supply to low-latitude surface waters? 2) What sources of nitrogen fuel export production in surface waters across the Pacific? 3) What are the roles in surface and subsurface processes in the distribution of nitrate isotopes in the ocean interior?

硝酸盐是海洋植物和藻类生长需求的重要营养。它在深海水域中很丰富，但在大多数阳光地表水中稀少。该项目的目的是更好地了解是什么控制了深海中硝酸盐的可用性及其向地表水的传递。斯坦福大学，普林斯顿大学和布朗大学的研究人员将分析太平洋中阿拉斯加和大溪地之间收集的硝酸盐稳定同位素。数据将提供有关硝酸盐向太平洋大部分地区供应的信息，并就海洋光合作用的过去和将来变化允许明智的决定。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。这项研究将包括三个学术机构的本科，研究生和博士后研究人员。调查人员将为普林斯顿大学中学和高中老师的学者计划开展为期1天的讲习班。该研讨会将着重于访问和可视化海洋数据集和Internet上可用的其他内容，以在课堂上进行基于项目的学习。调查人员还将参加每年夏天在斯坦福大学举办的教师研讨会。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。数据还将在将免费提供的地理位置数据产品中编译。海洋内部记录中硝酸盐的同位素组成在数年，几十年，几个世纪和千年的时间尺度上，具有浅层地下和深海记录的时间尺度，分别较短，并且分别更短，并且分别更短。这些是有意义的时间尺度（1）了解构建海洋，海洋生产力和全球碳周期的生物地球化学的反馈，（2）重建过去的海洋生物地球化学和碳循环的变化，以及（3）也许可以预测未来的变化。该提案旨在分析即将到来的美国地理特种液在阿拉斯加和塔希提岛之间的硝酸盐同位素。硝酸盐同位素对海洋N周期和预算提供了关键的限制，尤其是在太平洋，各种过程影响硝酸盐的分布及其对地表水的供应。硝酸盐同位素数据的这一主要子午线部分将是全球海洋增长的硝酸盐同位素数据集的一部分，并与许多互补的地球化学数据集进行比较，这些数据集将作为这项地理词努力的一部分生成。另外，将测量气溶胶中的硝酸盐同位素以支持沿截面沿地表水中硝酸盐同位素的解释。拟议的测量将有助于研究三个总体问题：1）太平洋盆地不同营养丰富的地区之间N生物地球化学的相似之处和差异是什么：南大洋，赤道太平洋和北太平洋北太平洋，以及如何影响硝酸盐供应到低升高地表水的硝酸盐供应？ 2）在太平洋地区的地表水域中，氮气燃料出口产量的哪些来源？ 3）在海洋内部硝酸盐同位素分布中，表面和地下过程中的作用是什么？

项目成果

The Agulhas Current Transports Signals of Local and Remote Indian Ocean Nitrogen Cycling

• DOI: 10.1029/2022jc019413
• 发表时间: 2023-03-01
• 期刊: JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
• 影响因子: 3.6
• 作者: Marshall, Tanya A.;Sigman, Daniel M.;Fawcett, Sarah E.
• 通讯作者: Fawcett, Sarah E.

Correction to “Global Nitrogen Cycle: Critical Enzymes, Organisms, and Processes for Nitrogen Budgets and Dynamics”

修正“全球氮循环：氮预算和动态的关键酶、生物体和过程”

• DOI: 10.1021/acs.chemrev.0c00743
• 发表时间: 2020
• 期刊: Chemical Reviews
• 影响因子: 62.1
• 作者: Zhang, Xinning;Ward, Bess B.;Sigman, Daniel M.
• 通讯作者: Sigman, Daniel M.

Ice Age‐Holocene Similarity of Foraminifera‐Bound Nitrogen Isotope Ratios in the Eastern Equatorial Pacific

• DOI: 10.1029/2020pa004063
• 发表时间: 2021-04
• 期刊: Paleoceanography and Paleoclimatology
• 影响因子: 3.5
• 作者: A. Studer;F. Mekik;H. Ren;M. Hain;S. Oleynik;A. Martínez-García;G. Haug;D. Sigman

Nitrogen isotopic constraints on nutrient transport to the upper ocean

• DOI: 10.1038/s41561-021-00836-8
• 发表时间: 2021-11-01
• 期刊: NATURE GEOSCIENCE
• 影响因子: 18.3
• 作者: Fripiat, Francois;Martinez-Garcia, Alfredo;Haug, Gerald H.
• 通讯作者: Haug, Gerald H.