Collaborative Research: US GEOTRACES GP17-ANT: Dissolved concentrations, isotopes, and colloids of the bioactive trace metals

合作研究：美国 GEOTRACES GP17-ANT：生物活性痕量金属的溶解浓度、同位素和胶体

基本信息

批准号：
2123333
负责人：
Jessica Fitzsimmons
金额：
$ 41.02万
依托单位：
Texas A&M University
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2021
资助国家：
美国
起止时间：
2021-10-01 至 2024-09-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2123333&HistoricalAwards=false
关键词：
Collaborative Research US GEOTRACES GP17

项目摘要

The goal of the international GEOTRACES program is to understand the distributions of trace chemical elements and their isotopes (TEIs) in the oceans. Many trace metals such as iron are essential for life and thus considered nutrients for phytoplankton growth, with trace metal cycling being especially important for influencing carbon cycling in the iron-limited Southern Ocean, where episodic supply of iron from a range of different external sources is important. The primary goal of this project is to measure the dissolved concentrations, size partitioning, and dissolved isotope signature of Fe on a transect of water-column stations throughout the Amundsen Sea and surrounding region of the Antarctic Margin, as part of the GP17-ANT Expedition. The secondary goal of this project is to analyze the concentrations and size partitioning of the trace metals manganese, zinc, copper, cadmium, nickel, and lead in all water-column samples, measure the isotope ratios of zinc, cadmium, nickel, and copper in a subset of water column samples, and measure the Fe isotopic signature of aerosols, porewaters, and particles. Observations from this project will be incorporated into regional and global biogeochemistry models to assess TEI cycling within the Amundsen Sea and implications for the wider Southern Ocean. This project spans three institutions, four graduate students, undergraduate students, and will provide ultrafiltered samples and data to other PIs as service.The US GEOTRACES GP17 ANT expedition, planned for austral summer 2023/2024 aims to determine the distribution and cycling of trace elements and their isotopes in the Amundsen Sea Sector (100-135°W) of the Antarctic Margin. The cruise will follow the Amundsen Sea ‘conveyor belt’ by sampling waters coming from the Antarctic Circumpolar Current onto the continental shelf, including near the Dotson and Pine Island ice shelves, the productive Amundsen Sea Polynya (ASP), and outflowing waters. Episodic addition of dissolved Fe and other TEIs from dust, ice-shelves, melting ice, and sediments drive seasonal primary productivity and carbon export over the Antarctic shelf and offshore into Southern Ocean. Seasonal coastal polynyas such as the highly productive ASP thus act as key levers on global carbon cycling. However, field observations of TEIs in such regions remain scarce, and biogeochemical cycling processes are poorly captured in models of ocean biogeochemistry. The investigators will use their combined analytical toolbox, in collaboration with the diagnostic chemical tracers and regional models of other funded groups to address four main objectives: 1) What is the relative importance of different sources in supplying Fe and other TEIs to the ASP? 2) What is the physiochemical speciation of this Fe, and its potential for transport? 3) How do biological uptake, scavenging and regeneration in the ASP influence TEI distributions, stoichiometry, and nutrient limitation? 4) What is the flux and signature of TEIs transported offshore to the ACC and Southern Ocean?This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

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（TEIS）在海洋中的分布。许多痕量金属（例如铁）对生命至关重要，因此被认为是浮游植物生长的养分，痕量金属循环对于影响碳循环的南大洋尤其重要，那里的碳循环是从一系列不同的外部来源的偶发性铁供应。该项目的主要目标是测量在整个阿蒙森海及其周边地区的溶解浓度，大小分配和溶解的Fe的同位素特征，作为GP17-远征的一部分。 The secondary goal of this project is to analyze the concentrations and size partitioning of the trace metals manganese, zinc, copper, cadmium, nickel, and lead in all water-column samples, Measure the isotope ratios of zinc, cadmium, nickel, and copper in a subset of water column samples, and measure the Fe isotopic signature of aerosols, porewaters, and particles.该项目的观察结果将纳入区域和全球生物地球化学模型中，以评估Amundsen海中的TEI骑自行车，并对南方大洋的影响。该项目涵盖了三个机构，四名研究生，本科生，并将向其他PI提供超过滤样本和数据作为服务。巡航将通过将来自南极圆形极电流的水采样到大陆架上，包括Dotson和Pine Island Ice架，生产性的Amundsen Sea Polynya（ASP）和流水的水，将沿着Amundsen Sea“传送带”。从灰尘，冰壳，融化的冰和沉积物中散发出溶解的FE和其他TEI驱动了季节性的初级生产力和碳出口，并在南极的架子上和海上进入南大洋。因此，季节性的沿海Polynyas（例如高效的ASP）是全球碳循环的关键杠杆。然而，在此类地区对TEI的现场观察仍然很少，并且在海洋生物地球化学模型中，生物地球化学循环过程被捕获的很差。研究人员将使用其组合的分析工具箱，与其他资助组的诊断化学示踪剂和区域模型合作解决四个主要目标：1）不同来源在向ASP提供FE和其他TEI的相对重要性是什么？ 2）该铁的生理化学规范及其运输的潜力是什么？ 3）ASP的生物摄取，清除和再生如何影响TEI分布，化学计量和营养限制？ 4）TEIS的通往ACC和南大洋的TEIS的通量和签名是什么？该奖项反映了NSF的坚定任务，并使用基金会的知识分子优点和更广泛的影响审查标准，被认为是通过评估而被视为珍贵的。