Collaborative Research: US GEOTRACES Arctic section; Nd and REE cycling in the Arctic Ocean

合作研究：美国GEOTRACES北极部分；

• 批准号: 1458936
• 负责人: Howard Scher
• 金额: $ 16.69万
• 依托单位: University of South Carolina at Columbia
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-03-15 至 2018-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1458936&HistoricalAwards=false
• 关键词: Collaborative; Research; US; GEOTRACES; Arctic

In this project, investigators participating in the 2015 U.S. GEOTRACES Arctic expedition will measure neodymium isotopes and rare earth elements in seawater, sediment, and particulates collected from the western Arctic Ocean. In common with other national initiatives in the International GEOTRACES Program, the goals of the U.S. Arctic expedition are to identify processes and quantify fluxes that control the distributions of key trace elements and isotopes in the ocean, and to establish the sensitivity of these distributions to changing environmental conditions. Some trace elements are essential to life, others are known biological toxins, and still others are important because they can be used as tracers of a variety of physical, chemical, and biological processes in the sea. Neodymium and rare earth elements are oceanographic tracers, and data from this research will provide benchmarks for other trace element and isotope studies to better understand their cycles and how future environmental changes will impact this important ocean basin. The project will support the training of undergraduate, graduate, and post-doctoral researchers, and results will be disseminated via public outreach activities.Neodymium (Nd) isotopes are tracers of water mass sources, transport and mixing, and rare earth elements (REEs) show systematic fractionations during environmental processes. Together they provide a powerful tool for analyzing provenances and processes in the oceans that reflect the changing environmental controls on the distribution of trace elements and their isotopes (TEIs). Inherent logistical difficulties make the Arctic Ocean especially scarce in TEI data (including Nd isotopes and REE concentrations), which hinders understanding and application of these tracers. In this study, researchers will examine Nd and REE concentrations in seawater, sediment, and particulate samples collected in the western Arctic Ocean, with the aim of (1) assessing Arctic circulation and water mass mixing in light of Nd isotopes and REEs; (2) attempting to quantify particle-dissolved exchanges of TEIs and; (3) using Nd isotopes and REEs to characterize the sources, sinks and exchanges of TEIs. It is expected that through improved understanding of the Nd isotope and REEs tracers, scientists will be able to relate these findings to other TEIs and to the broader understanding of Arctic oceanographic change in the past, present, and future.

在该项目中，参加2015年美国地理探险队的调查人员将测量从西部北极海洋收集的海水，沉积物和颗粒物中的新近植物和稀土元素。美国北极探险队的目标是与国际地理计划计划中的其他国家倡议共同确定过程，并量化控制海洋中关键的微量元素和同位素分布的通量，并确定这些分布对改变环境条件的敏感性。一些痕量元素对生命至关重要，另一些是已知的生物毒素，而另一些则很重要，因为它们可以用作海洋中各种物理，化学和生物过程的示踪剂。霓虹灯和稀土元素是海洋示踪剂，这项研究的数据将为其他痕量元素和同位素研究提供基准，以更好地了解它们的周期以及未来的环境变化将如何影响这个重要的海洋盆地。该项目将支持本科，研究生和博士后研究人员的培训，结果将通过公共外展活动传播。Neodymium（ND）同位素是水质量来源，运输和混合的示踪剂，稀土元素（REAS）在环境过程中显示出系统的分馏。它们共同提供了一个强大的工具，用于分析海洋中的证明和过程，反映了痕量元素及其同位素（TEIS）的环境控制变化的不断变化。固有的后勤困难使北极海洋在TEI数据中尤其稀缺（包括ND同位素和REE浓度），从而阻碍了这些示踪剂的理解和应用。在这项研究中，研究人员将研究在西部北极海洋中收集的海水，沉积物和颗粒样品中的ND和REE浓度，以（1）评估ND同位素和REE的北极循环和水量混合； （2）试图量化Teis的粒子溶解的交换； （3）使用ND同位素和REE来表征TEI的来源，下沉和交换。可以预期，通过对ND同位素和REES示踪剂的了解，科学家将能够将这些发现与其他TEI相关联以及对过去，现在和将来的北极海洋学变化的更广泛的理解。