Collaborative Research: Lead-210 and Polonium-210 as tracers for scavenging and export: GEOTRACES Pacific Meridional Section

合作研究：铅 210 和钋 210 作为清除和出口示踪剂：GEOTRACES 太平洋子午线部分

• 批准号: 1736612
• 负责人: Mark Stephens
• 金额: $ 24.46万
• 依托单位: Florida International University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-15 至 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1736612&HistoricalAwards=false
• 关键词: Collaborative; Research; Lead; 210; Polonium

The goal of the international GEOTRACES program is to understand the distributions of trace chemical elements and their isotopes in the oceans. These chemical species play important roles in the ocean as nutrients, tracers of current and past oceanographic processes, and as contaminants from human activity. Their biogeochemical cycling has direct implications for research in such diverse areas as the carbon cycle, climate change, and ocean ecosystems. This project will use measurement of two natural radionuclides -- lead-210 and polonium-210 -- to provide important information about the rates of processes that affect trace elements and isotopes (TEIs) that will be measured during a U.S. GEOTRACES expedition in the Pacific Ocean in 2018. The research proposed here will address key tasks formulated within the GEOTRACES Science Plan. Many processes in the ocean cannot be observed directly but tracers such as polonium-210 (half-life = 138 days) and lead-210 (half-life = 22.3 years) that have unique chemical properties and relevant decay timescales can be used to provide important constraints on their rates and pathways. The goals of this research are to: 1) use Pb-210, along with another project measuring Be-7, in aerosols and precipitation to characterize aerosol and TEI sources, 2) determine scavenging rates of particle-reactive TEIs through the water column using Po-210 and Pb-210, 3) use Po-210 / Pb-210 disequilibrium in the upper water column as a proxy for the sinking flux of particulate organic carbon (POC), and 4) use Pb-210as a tracer of the influence of hydrothermal processes on water column distributions of TEIs. This work will build on a database of Po/Pb distributions in the world ocean (and the Pacific Ocean, in particular) obtained through programs such as GEOSECS, GEOTRACES, and independent studies. A graduate student will be trained as part of this project. The lead investigator, Cochran, plans to incorporate information about GEOTRACES sampling strategies in the planning for a travelling exhibition on "The Oceans" through his adjunct appointment at the American Museum of Natural History (New York). Project partner Kadko plans to incorporate GEOTRACES work in an international graduate course through the Nippon Foundation, Partnership for Observation of the Global Oceans Center of Excellence.

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在海洋中的分布。这些化学物质在海洋中起着重要作用，作为养分，当前和过去海洋学过程的示踪剂，以及人类活动的污染物。他们的生物地球化学自行车对诸如碳循环，气候变化和海洋生态系统等各个领域的研究具有直接影响。该项目将使用两种天然放射性核素（Lead-210和Polonium-210）的测量，以提供有关影响痕量元素和同位素（TEI）的过程速率的重要信息，这些过程将在2018年在太平洋的美国地理探险中进行测量。此处提出的研究将解决GEOTRASE Science Science Science中的关键任务。无法直接观察到海洋中的许多过程，但是示踪剂，例如Polonium-210（半衰期= 138天）和Lead-210（半衰期= 22.3岁），具有独特的化学性质和相关的衰减时间表，可用于对其速率和途径提供重要约束。这项研究的目标是：1）使用PB-210，以及另一个测量BE-7的项目，在气溶胶和降水中以表征气溶胶和TEI来源，2）确定使用PO-210和PB-210，3）确定通过水柱通过po-210 / pb-210 disequilibile in Ornalulation disequilibile的粒子反应TEIS的清除速率，将其独特地置于限制范围。 （POC）和4）使用PB-210 AS A示踪热液过程对TEIS水柱分布的影响。这项工作将基于通过GeoSecs，Geotraces和独立研究等计划获得的世界海洋（尤其是太平洋）的PO/PB分布数据库。研究生将作为该项目的一部分进行培训。首席调查员科克伦计划通过他在美国自然历史博物馆（纽约）的兼职任命（纽约）的兼职任命，将有关地理品的抽样策略的信息纳入“海洋”的巡回展览。项目合作伙伴Kadko计划通过Nippon Foundation（观察全球海洋卓越中心的伙伴关系）将Geotraces的工作纳入国际研究生课程。

项目成果

210 Pb and 7 Be as Coupled Flux and Source Tracers for Aerosols in the Pacific Ocean

210 Pb 和 7 Be 作为太平洋气溶胶的耦合通量和源示踪剂

• DOI: 10.1029/2022gb007378
• 发表时间: 2022
• 期刊: Global Biogeochemical Cycles
• 影响因子: 5.2
• 作者: Wei, Ziran;Cochran, J. Kirk;Horowitz, Evan;Fitzgerald, Patrick;Heilbrun, Christina;Kadko, David;Stephens, Mark;Marsay, Chris M.;Buck, Clifton S.;Landing, William M.
• 通讯作者: Landing, William M.