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 计划的目标是了解海洋中许多化学元素及其同位素的分布。美国国家科学基金会正在支持 2018 年美国 GEOTRACES 太平洋采样考察，从阿拉斯加到塔希提岛。该奖项将重点测量本次探险中海水、过滤颗粒和大气气溶胶颗粒中铁 (Fe)、镍 (Ni)、锌 (Zn)、铜 (Cu) 和镉 (Cd) 的稳定同位素。微量金属 Fe、Ni、Zn、Cu 和 Cd 强烈影响海洋生物地球化学和碳循环。同位素比的测量（同一化学元素不同形式的相对丰度）提供了仅通过浓度测量无法获得的见解。研究人员将利用同位素数据来更多地了解这些元素对海洋的输入和输出，以及影响其在海洋内分布的生物过程，从而更好地了解这些金属在海洋碳循环中所发挥的作用。该奖项还将举办国际实验室间比较海水中低浓度镉同位素比率的活动。该项目将支持一名早期职业研究员、一名博士后研究员以及本科生和研究生。研究人员将沿着美国 GEOTRACES 太平洋经线横断面 (PMT) 以高空间分辨率测量 delta-56Fe、delta-60Ni、delta-65Cu、delta-66Zn 和 delta-114Cd。由此产生的所有五个同位素系统的海洋剖面将使他们能够区分有关控制痕量金属分布的相互竞争的想法。将探索和测试有关海洋生物地球化学痕量金属循环的各种假设，解决具有全球重要性的主题，包括：1）不同的来源、生产力和出口制度，加上翻转循环，如何控制铁、镍、太平洋中的锌、铜和镉及其同位素？ 2) 氧最低区是否充当 Cd、Zn、Cu 和 Ni 的汇，同时充当 Fe 的来源？ 3) 对于向北太平洋供应铁最重要的来源是什么？ PMT 部分穿过两个高营养低叶绿素 (HNLC) 区域和两个寡营养环流，并横切海洋中最古老的水域，使研究人员能够使用高分辨率同位素数据集来研究有关垂直、所有五种金属及其同位素分布的水平和原位生物地球化学过程。气溶胶尘埃、火山沉积物和减少边缘沉积物以及东太平洋海隆等热液喷口都被认为是太平洋溶解铁循环的主要贡献者。测量气溶胶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铁源和过程在向铁有限的表层海洋供应铁方面的重要性，对于 PMT 部分沿线的两个 HNLC 区域尤其重要。

项目成果

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

东部热带北太平洋缺氧区水柱中镍缺乏氧化还原循环：来自溶解和颗粒镍同位素的见解

• DOI: 10.1016/j.gca.2021.07.004
• 发表时间: 2021-09-15
• 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
• 通讯作者: S. John

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: 2022-01
• 期刊: Journal of Open Source Software
• 作者: Pasquier, Benoît;Primeau, François;John, Seth
• 通讯作者: John, Seth

GNOM v1.0: an optimized steady-state model of the modern marine neodymium cycle

GNOM v1.0：现代海洋钕循环的优化稳态模型

• DOI: 10.5194/gmd-15-4625-2022
• 发表时间: 2022-01
• 期刊: Geoscientific Model Development
• 影响因子: 5.1
• 作者: Pasquier, Benoît;Hines, Sophia K.;Liang, Hengdi;Wu, Yingzhe;Goldstein, Steven L.;John, Seth G.
• 通讯作者: John, Seth G.

A new purification method for Ni and Cu stable isotopes in seawater provides evidence for widespread Ni isotope fractionation by phytoplankton in the North Pacific

海水中镍和铜稳定同位素的新纯化方法为北太平洋浮游植物广泛进行镍同位素分馏提供了证据

• DOI: 10.1016/j.chemgeo.2020.119662
• 发表时间: 2020-08
• 期刊: Chemical Geology
• 影响因子: 3.9
• 作者: Yang, Shun;Hawco, Nicholas J.;Pinedo;Bian, Xiaopeng;Huang, Kuo;Zhang, Ruifeng;John, Seth G.
• 通讯作者: John, Seth G.

Biogeochemical cycling of Cd, Mn, and Ce in the Eastern Tropical North Pacific oxygen‐deficient zone

东部热带北太平洋缺氧区 Cd、Mn 和 Ce 的生物地球化学循环

• DOI: 10.1002/lno.12287
• 发表时间: 2022-12
• 期刊: Limnology and Oceanography
• 影响因子: 4.5
• 作者: Bian, Xiaopeng;Yang, Shun‐Chung;Bolster, Kenneth M.;Moriyasu, Rintaro;Moffett, James W.;John, Seth G.
• 通讯作者: John, Seth G.