U.S. GEOTRACES Pacific Meridional Transect: Tracing Basin-scale Nutrient Cycling and Carbon Export with Dissolved and Particulate Barium-isotopic Distributions

美国 GEOTRACES 太平洋经线横断面：通过溶解和颗粒钡同位素分布追踪盆地规模的养分循环和碳输出

基本信息

批准号：
1736949
负责人：
Tristan Horner
金额：
$ 39.35万
依托单位：
Woods Hole Oceanographic Institution
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2018
资助国家：
美国
起止时间：
2018-01-01 至 2021-12-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1736949&HistoricalAwards=false
关键词：
U.S.GEOTRACES Pacific Meridional Transect

项目摘要

The goal of the international GEOTRACES program is to understand the distributions of trace chemical elements and their isotopes in the oceans. This project would measure stable isotopes of barium on a 2018 U.S. GEOTRACES expedition in the Pacific Ocean. Barium is a trace element whose distribution is relevant to all three themes of the GEOTRACES program, as barium can be used to: study chemical cycling within the oceans; trace exchanges of elements at ocean boundaries; and infer past environmental conditions. The data collected here will be the first of their kind for barium isotopes and will illuminate the geochemical cycle of this element. Moreover, conducting this work as part of the GEOTRACES program will maximize the return on investment in the barium isotope data by providing a rich interpretative framework.This project seeks to understand how the interplay between internal cycling and boundary processes sets basin-scale barium concentration and isotopic distributions in the Pacific Ocean. Despite possessing a nutrient-like dissolved profile, marine barium cycling has a fundamentally different boundary condition to the major algal nutrients: barium cycling is not driven by production of organic matter but rather by its remineralization. Respiration of sinking organic matter in the ocean's 'twilight zone' releases carbon dioxide, mineralizes nutrients, and promotes precipitation of micron-size crystals of barite. Since barite is the major vector of particulate barium in seawater, the abundance and isotopic composition of barium in the oceans is tied to global carbon and nutrient cycling at the 'dark end' of the biological carbon pump. The data collected here will be used to test hypotheses across an unprecedented range of oceanographic conditions regarding: the formation, export, and regeneration of particulate material and the connection to seafloor processes; the importance of boundary sources to regional and global trace element and isotope budgets; the formation of putative soft-metal sulfides in oxygen-minimum zones; and the origin of enigmatic suspended particles in the deep open ocean. This proposal will contribute to education by training undergraduate research fellows and through presentation of seminars and guest lectures to regional science educators through collaboration with a regional conservation organization.

国际地理计划计划的目标是了解痕量化学元件及其同位素在海洋中的分布。该项目将在太平洋2018年的2018年美国地理探险中测量钡的稳定同位素。钡是痕量元素，其分布与地理位置计划的所有三个主题相关，因为钡可以用来：研究海洋内的化学循环；在海洋边界处的元素交换；并推断过去的环境条件。这里收集的数据将是钡同位素的第一个数据，并将阐明该元素的地球化学周期。此外，通过提供丰富的解释性框架，将这项工作作为Geotraces计划的一部分将最大程度地提高钡同位素数据的投资回报率。本项目旨在了解内部循环和边界过程之间的相互作用如何设置盆地规模的钡量和平均水平的同位素分布。尽管具有类似营养的溶解轮廓，但海洋钡骑自行车与主要藻类营养素的边界条件根本不同：钡循环不是由有机物的产生，而是由它的回忆化驱动。海洋“暮光区”中下沉有机物的呼吸可释放二氧化碳，矿化营养，并促进微尺寸少石晶体的沉淀。由于Barite是海水中颗粒钡的主要载体，因此海洋中钡的丰度和同位素组成与生物碳泵的“黑暗端”处的全球碳和营养循环相关。此处收集的数据将用于在空前的海洋条件范围内检验假设，涉及以下方式：颗粒物质的形成，出口和再生以及与海底过程的联系；边界来源对区域和全球痕量要素和同位素预算的重要性；最小氧气区域中假定的软金属硫化物的形成；以及深海中神秘的悬浮颗粒的起源。该建议将通过培训本科研究研究员以及通过与区域保护组织合作向区域科学教育工作者举办研讨会和嘉宾演讲来为教育做出贡献。

项目成果

期刊论文数量（10）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

A spatially and vertically resolved global grid of dissolved barium concentrations in seawater determined using Gaussian Process Regression machine learning

使用高斯过程回归机器学习确定海水中溶解钡浓度的空间和垂直解析全局网格

DOI：
10.26008/1912/bco-dmo.885506.2
发表时间：
2023
期刊：
Biological and Chemical Oceanography Data Management Office (BCO-DMO
影响因子：
0
作者：
Horner, Tristan J.;Mete, Oyku Z.
通讯作者：
Mete, Oyku Z.

Bioactive Trace Metals and Their Isotopes as Paleoproductivity Proxies: An Assessment Using GEOTRACES‐Era Data

生物活性微量金属及其同位素作为古生产力指标：使用 GEOTRACES Era 数据进行评估

DOI：
10.1029/2020gb006814
发表时间：
2021
期刊：
Global Biogeochemical Cycles
影响因子：
5.2
作者：
Horner, T. J.;Little, S. H.;Conway, T. M.;Farmer, J. R.;Hertzberg, J. E.;Janssen, D. J.;Lough, A. J. M.;McKay, J. L.;Tessin, A.;Galer, S. J. G.
通讯作者：
Galer, S. J. G.

Barium in deep-sea bamboo corals: Phase associations, barium stable isotopes, & prospects for paleoceanography

DOI：
10.1016/j.epsl.2019.115751
发表时间：
2019-11-01
期刊：
EARTH AND PLANETARY SCIENCE LETTERS
影响因子：
5.3
作者：
Geyman, Ben M.;Ptacek, Jamie L.;Horner, Tristan J.
通讯作者：
Horner, Tristan J.

Barium in seawater: dissolved distribution, relationship to silicon, and barite saturation state determined using machine learning

DOI：
10.5194/essd-15-4023-2023
发表时间：
2023-09
期刊：
Earth System Science Data
影响因子：
11.4
作者：
Öykü Z. Mete;A. Subhas;Heather H. Kim;A. Dunlea;L. Whitmore;A. Shiller;Melissa Gilbert;William D. Leavitt;Tristan J. Horner
通讯作者：
Öykü Z. Mete;A. Subhas;Heather H. Kim;A. Dunlea;L. Whitmore;A. Shiller;Melissa Gilbert;William D. Leavitt;Tristan J. Horner

Barium isotope signatures of barite–fluid ion exchange in Equatorial Pacific sediments