| 项目编号: | 1435376
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| 项目名称: | GEOTRACES Arctic Section: Disequilibria between Radium-226, Lead-210 and Polonium-210 in the Arctic Ocean and their implications for trace metal distribution |
| 作者: | Kanchan Maiti
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| 承担单位: | Louisiana State University & Agricultural and Mechanical College
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| 批准年: | 2014
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| 开始日期: | 2015-01-15
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| 结束日期: | 2018-12-31
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| 资助金额: | USD186119
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| 资助来源: | US-NSF
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| 项目类别: | Standard Grant
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| 国家: | US
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| 语种: | 英语
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| 特色学科分类: | Geosciences - Polar
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| 英文关键词: | lead-210
; polonium-210
; half-life
; lead-210 distribution
; distribution
; u. s. arctic expedition
; arctic region
; polonium
; lead change
; tei distribution
; project
; particle
; scavenging intensity
; area
; process
; arctic geotraces section
; key trace element
; international geotraces program
; trace element
; arctic geotraces outreach program
; lead investigator
; radionuclide radium-226
; u. s. geotraces arctic expedition
; region
|
| 英文摘要: | This project will form part of the 2015 U.S. GEOTRACES Arctic expedition. In common with other multinational initiatives in the International GEOTRACES Program, the goals of the U.S. Arctic expedition are to identify processes and quantify fluxes that control the distributions of key trace elements and isotopes (TEIs) in the ocean, and to establish the sensitivity of these distributions to changing environmental conditions. Some trace elements are essential to life, others are known biological toxins, and still others are important because they can be used as tracers of a variety of physical, chemical, and biological processes in the sea. Within this broader framework, the goal of this project is to measure the naturally occurring radionuclides radium-226 (half-life 1600 years), lead-210 (half-life 22.1 y) and polonium-210 (half-life 138 days) to determine removal rates of particle reactive TEIs from the water column and to study the processes responsible for their scavenging, lateral and vertical transport and accumulation in bottom sediments. A wide range of processes will be encountered along the proposed ARCTIC GEOTRACES section and the proposed study will play a key role in the interpretation of observed TEI distributions and address the following questions: (1) What is the variability in scavenging intensity of polonium and lead between the Pacific waters and that of particle dominated areas of the shelf? (2) How does the scavenging intensity of polonium and lead change across areas of varying nutrient concentrations in the Chukchi Sea? (3) How does the scavenging intensity vary between Canadian Basin and the Makarov Basin? (4) Which are the areas of enhanced sediment focusing in this region and how important is the role of boundary scavenging and lateral transport of particles with respect to lead-210 distribution in water column and sediments? (5) What are the seasonal scale vertical fluxes of particulate organic matter in this region and the relative importance of lateral versus vertical transport of organic matter and other TEIs? (6) How do particle mixing rates vary across the basin and impact reduction rates? (7) Are the bottom waters in the shelf region enriched in polonium-210 due to sediment remobilization? The ability to address these questions will allow better understanding of processes controlling the distribution in this region of other TEIs that will be measured by other investigators. The broader impacts of the research include the involvement of 1 Ph.D. student and at least 2 undergraduate students. The lead investigator is an early-career scientist and this project will help him in extending his expertise in the Arctic region and further development of his career. The investigator is involved in numerous local outreach activities that will provide opportunities for education of the general public and high school students about marine ecosystems and how it affects their environmental well-being. Moreover this research will also be a part of the broader Arctic GEOTRACES outreach program which plans to support the participation of a high-school science teacher on the cruise through partnership with PolarTREC and COSEE-Alaska. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/95206
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| Appears in Collections: | 影响、适应和脆弱性
气候减缓与适应
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| Recommended Citation: | |
Kanchan Maiti. GEOTRACES Arctic Section: Disequilibria between Radium-226, Lead-210 and Polonium-210 in the Arctic Ocean and their implications for trace metal distribution. 2014-01-01.
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