Collaborative research: US GEOTRACES PMT: Trace-metal concentrations and stable isotopes in the North Pacific

合作研究：美国 GEOTRACES PMT：北太平洋的痕量金属浓度和稳定同位素

• 批准号: 1736896
• 负责人: Seth John
• 金额: $ 44.02万
• 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: 2017
• 资助国家: 美国
• 起止时间: 2017-08-15 至 2022-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1736896&HistoricalAwards=false
• 关键词: Collaborative; research; US; GEOTRACES; PMT

The goal of the international GEOTRACES program is to understand the distributions of many chemical elements and their isotopes in the oceans. The National Science Foundation is supporting a U.S. GEOTRACES sampling expedition in the Pacific Ocean 2018, from Alaska to Tahiti. This award will focus on measurement of the stable isotopes of iron (Fe), nickel (Ni), zinc (Zn), copper (Cu), and cadmium (Cd) in seawater, filtered particles, and atmospheric aerosol particles on this expedition. The trace metals Fe, Ni, Zn, Cu, and Cd strongly influence marine biogeochemistry and carbon cycling. Measurements of isotope ratios -- the relative abundance of different forms of the same chemical element -- provide insights not possible from concentration measurements alone. The investigators will use isotope data to learn more about the inputs and outputs of these elements to the ocean as well as the biological processes that influence their distributions within the oceans, leading to greater understanding of the role these metals play in oceanic carbon cycling. The award will also host an international inter-lab comparison exercise for Cd isotope ratios at low concentrations in seawater. The project will support an early career investigator, a postdoctoral researcher, and undergraduate and graduate students. The investigators will measure delta-56Fe, delta-60Ni, delta-65Cu, delta-66Zn, and delta-114Cd at high spatial resolution along the U.S. GEOTRACES Pacific Meridional Transect (PMT). The resulting oceanic sections of all five isotope systems will enable them to distinguish between competing ideas about the controls on trace metal distributions. A wide variety of hypotheses about marine biogeochemical trace metal cycling, addressing topics of global importance will be explored and tested, including: 1) How do different sources, productivity and export regimes, coupled with overturning circulation, control the distribution of Fe, Ni, Zn, Cu and Cd and their isotopes in the Pacific? 2) Do oxygen minimum zones act as sinks for Cd, Zn, Cu and Ni, while acting as sources for Fe? and 3) What sources are most important for supplying Fe to the North Pacific Ocean? The PMT section crosses two high nutrient-low chlorophyll (HNLC) regions and two oligotrophic gyres, as well as transecting the oldest waters in the ocean, allowing the investigators to use high-resolution isotope datasets to investigate competing hypotheses about the effect of vertical, horizontal and in situ biogeochemical processes on the distribution of all five metals and their isotopes. Aerosol dust, volcanogenic and reducing margin sediments, and hydrothermal vents such as the East Pacific Rise have all been hypothesized as major contributors to the dissolved Fe cycle in the Pacific. Measurement of iron isotope signatures in aerosols and near to oceanic sources will enable the identification and quantification the importance of these different iron sources and processes in supplying iron to the iron-limited surface ocean, especially important for the two HNLC regions along the PMT section.

国际GEOTRACES计划的目标是了解许多化学元素及其同位素在海洋中的分布。美国国家科学基金会正在支持美国GEOTRACES 2018年在太平洋从阿拉斯加到塔希提岛的采样考察。该奖项将重点关注此次考察中海水、过滤颗粒物和大气气溶胶颗粒物中铁（Fe）、镍（Ni）、锌（Zn）、铜（Cu）和镉（Cd）的稳定同位素的测量。微量元素Fe、Ni、Zn、Cu和Cd对海洋生态地球化学和碳循环有重要影响。同位素比率的测量----同一种化学元素不同形式的相对丰度----提供了仅靠浓度测量不可能得到的见解。研究人员将利用同位素数据更多地了解这些元素对海洋的输入和输出，以及影响其在海洋中分布的生物过程，从而更好地了解这些金属在海洋碳循环中的作用。该奖项还将举办一个国际实验室间的比较演习，在海水中低浓度的镉同位素比率。该项目将支持一个早期的职业调查员，博士后研究员，本科生和研究生。研究人员将沿着美国GEOTRACES太平洋子午线样带（PMT）以高空间分辨率测量δ-56 Fe，δ-60 Ni，δ-65 Cu，δ-66 Zn和δ-114 Cd。由此产生的所有五种同位素系统的海洋部分将使他们能够区分关于控制痕量金属分布的竞争性想法。将探讨和检验关于海洋地球化学痕量金属循环的各种各样的假设，涉及具有全球重要性的主题，包括：1）不同的来源、生产力和输出机制，加上翻转环流，如何控制铁、镍、锌、铜和镉及其同位素在太平洋的分布？2)氧气最小区是否充当Cd、Zn、Cu和Ni的汇，而充当Fe的源？（3）北太平洋Fe的主要来源是什么？PMT部分跨越两个高营养低叶绿素（HNLC）区域和两个寡营养环流，以及横切海洋中最古老的沃茨，使研究人员能够使用高分辨率同位素数据集来调查关于垂直，水平和原位地球化学过程对所有五种金属及其同位素分布的影响的相互竞争的假设。气溶胶尘埃，火山和还原边缘沉积物，以及热液喷口，如东太平洋隆起都被假设为太平洋溶解铁循环的主要贡献者。测量气溶胶中和海洋源附近的铁同位素特征将能够识别和量化这些不同的铁源和过程在向铁有限的表层海洋供应铁方面的重要性，特别是对于沿着PMT部分的两个HNLC区域而言。

项目成果

AIBECS.jl: A tool for exploring global marine biogeochemical cycles.

AIBECS.jl：探索全球海洋生物地球化学循环的工具。

• DOI: 10.21105/joss.03814
• 发表时间: 2022
• 期刊: Journal of Open Source Software
• 作者: Pasquier, Benoît;Primeau, François;John, Seth
• 通讯作者: John, Seth

Distribution patterns of dissolved trace metals (Fe, Ni, Cu, Zn, Cd, and Pb) in China marginal seas during the GEOTRACES GP06-CN cruise

• DOI: 10.1016/j.chemgeo.2022.120948
• 发表时间: 2022-05
• 期刊: Chemical Geology
• 影响因子: 3.9
• 作者: Ruifeng Zhang;J. Ren;Zhaoru Zhang;Zhu Zhu-Zhu;S. John

Lack of redox cycling for nickel in the water column of the Eastern tropical north pacific oxygen deficient zone: Insight from dissolved and particulate nickel isotopes

• DOI: 10.1016/j.gca.2021.07.004
• 发表时间: 2021-09
• 期刊: Geochimica et Cosmochimica Acta
• 影响因子: 5
• 作者: Shun‐Chung Yang;Rachel L. Kelly;X. Bian;T. Conway;Kuo‐Fang Huang;T. Ho;Jacquelyn A. Neibauer;R. Keil;J. Moffett;S. John

The biogeochemical balance of oceanic nickel cycling

海洋镍循环的生物地球化学平衡

• DOI: 10.1038/s41561-022-01045-7
• 发表时间: 2022
• 期刊: Nature Geoscience
• 影响因子: 18.3
• 作者: John, Seth G.;Kelly, Rachel L.;Bian, Xiaopeng;Fu, Feixue;Smith, M. Isabel;Lanning, Nathan T.;Liang, Hengdi;Pasquier, Benoît;Seelen, Emily A.;Holzer, Mark
• 通讯作者: Holzer, Mark

Delivery of Metals and Dissolved Black Carbon to the Southern California Coastal Ocean via Aerosols and Floodwaters Following the 2017 Thomas Fire

• DOI: 10.1029/2020jg006117
• 发表时间: 2021-02
• 期刊: Journal of Geophysical Research: Biogeosciences
• 作者: Rachel L. Kelly;X. Bian;S. Feakins;K. Fornace;T. Gunderson;N. Hawco;Hengdi Liang;J. Niggemann;Suzanne E. Paulson;P. Pinedo‐González;A. Joshua West;Shun‐Chung Yang;Seth G. John