Collaborative Research: US GEOTRACES GP17-ANT: Tracing Inputs and Transport of Aluminum, Manganese, and Iron from the Amundsen Sea Sector of the Antarctic Continental Margin

合作研究：美国 GEOTRACES GP17-ANT：追踪南极大陆边缘阿蒙森海区铝、锰和铁的输入和运输

• 批准号: 2148091
• 负责人: Joseph Resing
• 金额: $ 26.84万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2148091&HistoricalAwards=false
• 关键词: Collaborative; Research; US; GEOTRACES; GP17

The international GEOTRACES program seeks to understand the distributions of trace elements and their isotopes in the oceans. As part of this effort, the US GEOTRACES program will undertake the GP17-ANT research cruise in November 2023-January 2024, with a focus on the distribution of trace elements and isotopes in the Amundsen Sea sector of the Southern Ocean. Biological production in the Southern Ocean plays an important role in regulating atmospheric carbon dioxide via biological uptake and the associated transfer of organic matter into the ocean interior. Most of this ocean region has abundant major nutrients (nitrogen, phosphorous and silicon) required for phytoplankton growth, but is deficient in the essential micronutrient iron. This means that phytoplankton growth during the summer growing season is regulated by iron. Other trace elements, such as manganese and cobalt, may also hold importance in this context. Hence, there is a compelling need to constrain the sources of these micronutrient trace elements to Southern Ocean surface waters. Chief among these sources are sediments, glaciers and sea ice on the Antarctic continental margins. This project seeks to advance understanding of the sources and transport of the micronutrients iron and manganese in the Amundsen Sea sector of the Southern Ocean, as part of the upcoming GEOTRACES GP17-ANT research expedition. The Amundsen Sea is a highly productive section of the Antarctic continental margin that is bordered by some of Antarctica’s most rapidly melting glacial ice shelves, and is thought to provide an important source of dissolved iron to the adjacent, iron-deficient surface waters of the Antarctic Circumpolar Current. As such, the measurements of trace elements and isotopes during this expedition will provide a critically important benchmark to assess the impacts of major changes that are anticipated for this marine environment during the coming decades, such as inputs of the micronutrient iron that are associated with increased glacial melting. The project involves two US laboratories, and will support the research of a graduate student and an undergraduate student. The project also includes the participation of a K-12 STEM education specialist who will develop educational outreach materials targeting elementary and middle school students and science teachers.In this project, the concentrations of trace elements that serve as micronutrients (dissolved iron and manganese) and tracers of inputs from continental dust and seafloor sediments (dissolved aluminum and manganese) will be measured in seawater samples collected during GP17-ANT. In addition, shipboard experiments will be performed to assess the potential for suspended particles and surface sediments to contribute these dissolved trace elements to surface seawater. This work, together with measurements of other trace elements and isotopes made by collaborators, will assess the sources, transport and chemical transformations of micronutrients in this sector of the Antarctic continental margin, and hence the trajectories of these micronutrient inputs in response to future environmental changes. The chemical analyses of dissolved aluminum, manganese and iron will be performed at sea, in near real-time, thus providing data to inform the cruise sampling strategy and guide the analyses of other investigators.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.

国际地理领域计划旨在了解痕量元素及其同位素在海洋中的分布。作为这项努力的一部分，美国的Geotraces计划将于2023年11月1日至2024年1月进行GP17-Ant Research巡游，重点是在南大洋的Amundsen Sea区的微量元素和同位素分布。南海中的生物生产在通过生物学摄取以及将有机物转移到海洋内部的情况下调节大气二氧化碳方面起着重要作用。该海洋地区的大部分地区都有丰富的主要营养素（氮，磷和硅），用于浮游植物生长，但在必需的微量营养素中缺乏。这意味着夏季生长季节的浮游植物生长受铁的调节。在这种情况下，其他微量元素（例如锰和钴）也可能很重要。因此，迫切需要将这些微量营养素的痕量元素限制为南部海洋地表水。这些来源中的主要是南极连续边缘的沉积物，冰川和海冰。作为即将到来的GEOTRACES GP17-ANT研究探险的一部分，该项目旨在提高对微量营养素和锰的资源和运输的理解。 Amundsen Sea是南极连续边缘的高生产力部分，与南极最快速熔化的冰川冰架接壤，被认为为溶解铁提供了重要的溶解铁的来源。因此，在此探险期间的微量元素和同位素的测量将提供一个至关重要的基准，以评估未来几十年中预期对这种海洋环境的重大变化的影响，例如与冰川融化增加有关的微量营养铁的投入。该项目涉及两个美国实验室，并将支持研究生和一名本科生的研究。该项目还包括一名K-12 STEM教育专家的参与，他将开发针对小学生和科学老师的教育外展材料。在这个项目中，作为微量营养素（溶解的铁和锰）的痕量元素的浓度以及持续的粉尘和海底的粉尘（分解型铝制脉冲）的示踪剂（溶解的粉尘）将是分裂的铝固定型固定型和曼植物，将是分解的氧化铝固定型螺栓固定的铝合物。 gp17-ant。此外，还将进行船上实验，以评估悬浮颗粒和表面沉积物的潜力，以促进这些溶解的痕量元素对地表海水。这项工作以及合作者制作的其他痕量元素和同位素的测量将评估南极连续边缘的微量营养素的来源，运输和化学转化，因此，这些微量营养素投入的轨迹会响应未来的环境变化。溶解的铝，锰和铁的化学分析将在海上实时进行，从而提供数据以告知巡航采样策略并指导其他研究人员的分析。该奖项反映了NSF的法定任务，并通过使用该基金会的知识分子优点和广泛的影响来评估NSF的法定任务，并被视为诚实的支持。