Atmospheric Trace Element Inputs to Surface Ocean Waters I: Lead Isotope Tracers in the Atlantic

大气痕量元素输入到表层海洋水域 I：大西洋中的铅同位素示踪剂

• 批准号: 9522004
• 负责人: Thomas Church
• 金额: $ 43.59万
• 依托单位: University of Delaware
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-11-01 至 1999-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9522004&HistoricalAwards=false
• 关键词: Atmospheric; Trace; Element; Inputs; Surface

9522004 Church Pb isotopes will be used as tracers to quantify the atmospheric inputs to and biogeochemical processes in the surface waters of the Sargasso Sea off Bermuda, and data will be gathered in the South Atlantic as part of a proposed third IOC trace element cruise during the same period. This is a coordinated effort between the University of Delaware Principal Investigators and other institutions. Included are those currently active in studies of the Bermuda atmosphere as part of the AEROCE program in its third phase with support from NSF-ATM, and other scientists investigating the major nutrient cycles, productivity, and associated carbon based flux (JGOFS-BATS and associated activities) in the waters off Bermuda under NSF-OCE support. Existing archived samples of precipitation and oceanic flux particles will be utilized first if they satisfy clean collection criteria. The proposed study will focus on the element Pb and its isotope tracers which include stable Pb (204,206,207,208), and the radioactive nuclide 210Pb with the associated parent/daughter pairs which are part of the series 226 Ra, 222Rn, 210Bi, and 210Po. Lead and its isotopes will be measured in individual and integrated atmospheric samples to be taken at the AEROCE Bermuda site, and on board several cruises off Bermuda. The radioactive lead (210Pb) and its disequilibrium with the daughters 210Bi and 210Po will reveal of atmospheric and surface ocean scavenging. The half lives of these isotopes (5 and 138 days respectively) should be commensurate with processes such as aqueous scavenging of particle reactive elements (such as Bi), and bio-active elements (such as Po). Through modeling of dissolved 210 Po profiles in the surface mixed layer down to the thermocline, eddy diffusion co-efficients in the surface waters will be determined and subsequently used to place constraints on new production rates. Generally, lead isotope modeling will constrain vertical and horizontal contribution s to the surface waters, and calibrate the mixing and particle scavenging of Pb.

小行星9522004 铅同位素将被用作示踪剂，以量化百慕大外海马尾藻海表层沃茨的大气输入和海洋地球化学过程，并将在南大西洋收集数据，作为同一期间海洋学委员会拟议的第三次微量元素考察的一部分。这是特拉华州大学首席研究员和其他机构之间的协调努力。其中包括目前积极参与百慕大大气研究的科学家，这是在国家科学基金-大气动力学研究中心的支持下进行的第三阶段AEROCE方案的一部分，以及在国家科学基金-海洋环境研究中心的支持下调查百慕大附近沃茨的主要营养循环、生产力和相关碳基通量（JGOFS-BATS和相关活动）的其他科学家。 如果降水和海洋通量粒子的现有存档样本符合清洁收集标准，将首先利用这些样本。 该研究将集中在元素Pb及其同位素示踪剂，包括稳定的Pb（204，206，207，208），以及放射性核素210 Pb及其相关的母/子对，这些母/子对是226 Ra，222 Rn，210 Bi和210 Po系列的一部分。 铅及其同位素将在AEROCE百慕大站点和百慕大附近的几次航行中采集的单个和综合大气样本中进行测量。放射性铅（~（210）Pb）及其与子体~（210）Bi和~（210）Po的不平衡，揭示了大气和海洋表面的清除作用。 这些同位素的半衰期（分别为5天和138天）应与诸如颗粒反应性元素（诸如Bi）和生物活性元素（诸如Po）的水清除过程相当。 通过模拟溶解210 Po剖面的表面混合层的温跃层，在表面沃茨的涡流扩散系数将被确定，并随后用于限制新的生产率。 一般来说，铅同位素模拟将限制垂直和水平的贡献s的表面沃茨，校准的混合和颗粒清除铅。