Collaborative Research: U.S. GEOTRACES North Atlantic Section: Analysis of 230Th, 232Th and 231Pa

合作研究：美国 GEOTRACES 北大西洋剖面：230Th、232Th 和 231Pa 分析

• 批准号: 0927757
• 负责人: Edward Durbin
• 金额: $ 19.6万
• 依托单位: University of Rhode Island
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-04-01 至 2015-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0927757&HistoricalAwards=false
• 关键词: Collaborative; Research; U.S.; GEOTRACES; North

In this project four collaborating labs -- Woods Hole Oceanographic Institution, University of Rhode Island, University of Minnesota and Lamont-Doherty -- will undertake measurements on the US GEOTRACES North Atlantic section of the dissolved and particulate concentrations of 230Th and 231Pa, two isotopes designated as "key" or critical to the success of the GEOTRACES program. In addition, they will measure 232Th concentrations and provide supporting analyses of particle composition. The proposed work fulfills scientific objectives defined in the U.S. GEOTRACES North Atlantic Implementation Plan. These new 231Pa, 230Th and 232Th data are expected to lead to improved models of material exchange between the boundaries and interior Atlantic on a basin-wide scale. This project will permit the research team and the marine radiogeochemical community to test hypotheses regarding the relative importance of regional variations in circulation, particle composition, and particle flux that influence the redistribution of particle-associated elements, including carbon, trace metals and contaminants, between the continental shelf/slope regions and interior basins in the Atlantic. Furthermore, obtaining new water column 231Pa and 230Th data will allow testing of a key hypothesis: that 230Th is largely removed within the North Atlantic, whereas nearly half of the 231Pa produced in-situ is exported with North Atlantic Deep Water. Sedimentary 231Pa/230Th ratios have become the principal proxy used to evaluate past changes in Atlantic Meridional Overturning Circulation (AMOC). Completing the proposed work will characterize the importance of particle composition for 231Pa/230Th fractionation, and thereby constrain the potential bias in using 231Pa/230Th as a kinematic proxy for AMOC. These results, in turn, will lead to a more reliable assessment of the role of AMOC variability in past climate change. Broader Impacts The hypotheses and objectives outlined in this proposal are central to the International GEOTRACES program, whose focus is on the global-ocean distribution of trace elements and isotopes in seawater. 231Pa and 230Th are designated key parameters in the GEOTRACES Science Plan as their measurement on all sections is deemed to be critical to the success of this international ocean science program. The proposed research will provide new opportunities for graduate student (LDEO) and post doc (UMinn) research experience, enhance ocean science interactions between several US institutions (LDEO, URI, UMinn, WHOI), foster collaboration with international GEOTRACES colleagues, and contribute to existing science education programs designed for teachers and the public.

在该项目中，四个合作实验室 - 明尼苏达大学和拉蒙特·霍尔蒂大学的伍兹霍尔海洋学机构 - 伍德斯霍尔海洋学机构，将在230届和231PA的溶解和微粒浓度的美国地理北大西洋北大西洋区进行测量。此外，它们将测量232浓度，并提供颗粒组成的支持分析。拟议的工作实现了美国北大西洋实施计划中定义的科学目标。这些新的231Pa，第230和232个数据有望在盆地范围内改善边界和内部大西洋之间的材料交换模型。该项目将允许研究团队和海洋射电地理学群落可以测试有关循环，颗粒组成和粒子通量中区域变化的相对重要性的假设，从而影响粒子相关元素的重新分布，包括碳，痕量金属和污染物，在大陆架子/slope/slope slope and slope区域和室内层之间的相对重要性。此外，获得新的水柱231Pa和第230个数据将允许测试一个关键的假设：在北大西洋中，第230个大部分是在北大西洋中取出的，而在北大西洋深水中产生的231pa中，近一半是在北大西洋上的一半。沉积231Pa/230th的比率已成为用于评估大西洋子午倾覆循环（AMOC）变化的主要代理。完成所提出的工作将表征粒子组成对231Pa/230分级分级的重要性，从而限制了使用231Pa/230th作为AMOC的运动代理时的潜在偏差。这些结果反过来将导致对AMOC变异性在过去气候变化中的作用的更可靠评估。该提案中概述的假设和目标的更广泛影响是国际地理计划计划的核心，该计划的重点是海水中痕量元素和同位素的全球分布分布。在Geotraces科学计划中，第231PA和第230位被指定为关键参数，因为它们对所有部分的测量都被认为对这项国际海洋科学计划的成功至关重要。拟议的研究将为研究生（LDEO）和Post Doc（Uminn）研究经验提供新的机会，增强了美国几个机构（LDEO，URI，UMINN，WHOI）之间的海洋科学互动，促进与国际地理领域的同事合作，并为专为教师和公众设计的现有科学教育计划做出贡献。