Collaborative Research:US GEOTRACES Pacific Zonal Transect: Rates of supply, removal and internal cycling of trace elements and isotopes

合作研究：US GEOTRACES 太平洋地带横断面：微量元素和同位素的供应、去除和内部循环率

• 批准号: 1232669
• 负责人: Ken Buesseler
• 金额: $ 110万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-12-01 至 2016-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1232669&HistoricalAwards=false
• 关键词: Collaborative; Research; US; GEOTRACES; Pacific

The goal of GEOTRACES is to identify processes and quantify fluxes that control the distribution of trace elements and isotopes (TEIs) in the ocean, and to establish the sensitivity of these distributions to changing environmental conditions. While the distribution of numerous TEIs will be mapped by a large team of GEOTRACES PIs along this transect, their distribution cannot be properly interpreted without concurrent measurement of tracers capable of providing rates of internal TEI cycling processes and fluxes at boundaries and across interfaces. Naturally-occurring radioisotopes of the Uranium-Thorium series are well suited for studying the sources and sinks of TEIs on time and space scales necessary to interpret lateral and vertical TEI distributions. In this project, a research team from the Woods Hole Oceanographic Institution and the University of South Carolina at Columbia will carry out measurement of a suite of uranium/thorium series radionuclides on the US GEOTRACES cruise to the Eastern Tropical South Pacific (ETSP) Ocean. This radiotracer suite will include shorter-lived 234Th and 228Th as well as the radium quartet (224Ra, 223Ra, 228Ra, 226Ra), which together allow the quantification of rates of horizontal and vertical transport and mixing, as well as removal at ocean boundaries, surface export, and subsurface remineralization. Broader Impacts: The PIs have actively involved undergraduate and high school students in their prior NSF-funded projects, with two having won awards at ASLO meetings in recent years. The trend will continue with this effort, along with the inclusion of an international guest student who will work on analytical improvements for measuring particulate 228Th. In addition, two WHOI-MIT Joint Program students will be involved using this project as a major part of their PhD theses on Th and Ra isotopes. Contributions to the data management side of the results from these 6 isotopes is eagerly awaited by the modeling community, where there is a lack of multiple thorium isotope data sets on these basin scales for parameterization of the cycling of all particle reactive and biologically active TEIs.

GEOTRACES 的目标是识别控制海洋中微量元素和同位素 (TEI) 分布的过程和量化通量，并确定这些分布对不断变化的环境条件的敏感性。 虽然许多 TEI 的分布将由一大群 GEOTRACES PI 沿该横断面绘制，但如果没有同时测量能够提供内部 TEI 循环过程速率以及边界和跨界面通量的示踪剂，则无法正确解释它们的分布。 铀-钍系列天然存在的放射性同位素非常适合在时间和空间尺度上研究 TEI 的源和汇，以解释横向和垂直 TEI 分布。在该项目中，伍兹霍尔海洋研究所和南卡罗来纳大学哥伦比亚分校的研究小组将在美国 GEOTRACES 前往东热带南太平洋（ETSP）海洋的航行中对一套铀/钍系列放射性核素进行测量。 该放射性示踪剂套件将包括寿命较短的 234Th 和 228Th 以及镭四重奏（224Ra、223Ra、228Ra、226Ra），它们一起可以量化水平和垂直传输和混合的速率，以及海洋边界的去除、表面出口和地下再矿化。更广泛的影响：PI 积极让本科生和高中生参与其之前的 NSF 资助项目，其中两人近年来在 ASLO 会议上获奖。这一趋势将继续下去，并邀请一名国际客座学生，他将致力于测量 228Th 颗粒物的分析改进。此外，两名 WHOI-MIT 联合项目学生将参与该项目，作为他们关于 Th 和 Ra 同位素的博士论文的主要部分。建模界热切期待这 6 种同位素结果对数据管理方面的贡献，因为这些盆地尺度上缺乏多个钍同位素数据集，无法对所有粒子反应性和生物活性 TEI 的循环进行参数化。