| 项目编号: | 1602533
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| 项目名称: | Collaborative Research: Arctic Land Fast Sea Ice Formation in the Presence of Fresh Water Input |
| 作者: | Ignatius Rigor
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| 承担单位: | University of Washington
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| 批准年: | 2016
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| 开始日期: | 2016-11-01
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| 结束日期: | 2019-10-31
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| 资助金额: | 177489
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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: | sea ice
; freshwater influence
; salinity
; growth season
; freshwater input
; significant fresh water input
; project
; ice core?the project
; seasonal cycle
; coastal ocean
; ice sheet
; freshwater runoff
; ice type
; ice core
; freshwater discharge
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| 英文摘要: | One of the most notable changes in the Arctic during recent years has been the variability in sea ice extent and timing. Changes in the character and seasonal cycle of nearshore sea ice is of particular importance to indigenous communities that use the nearshore sea ice as a platform for subsistence hunting and transportation. Observations and model projections also suggest increasing freshwater runoff to the coastal ocean from increased melting of glaciers and ice sheets, thawing of permafrost, and precipitation over land. This runoff impacts the sea ice that forms in the fall. Sea ice formed under freshwater influence reveals differences in salinity, porosity, and permeability, and thus its optical and mechanical properties. This project will provide unique observations of sea ice formation and structure under conditions of freshwater influence.
This project will contribute to STEM workforce development through provision of support for the training of a graduate student. It will also entrain undergraduate students from Dartmouth?s Women in Science Project (WISP). One undergraduate will participate in the spring field work. The project will also apply for support for a PolarTREC teacher. K-12th grade outreach activities will be offered and will leverage existing programs at University of Washington such as participation in the Polar Science Weekend at the Pacific Science Center.
The freshwater discharge to the coastal ocean affects thermodynamic processes in sea ice by changing salinity and temperature of the waters undergoing freezing. This three-year pilot project is designed to study sea ice formation and structure in the coastal ocean, while addressing the following important questions:
1. How do microstructure and the brine pocket network differ in sea ice that forms and grows where there is significant fresh water input compared to sea ice in the open ocean?
2. Can we monitor the onset of freezing, freezing rate and ice type in situ in sensitive nearshore areas, while collecting data remotely?
3. How does microstructure affect heat transfer along the length of an ice core?
The project will combine recently developed observation and sampling technologies, and integrate expertise in field monitoring, and physical and chemical sea ice characterization. Sea ice formation, growth rate, and salinity will be monitored in situ at a location of freshwater input during the course of a growth season using a wire ladder. Oxygen isotopic ratios and optical thin section stratigraphy will be used to quantify freshwater influence. X-ray micro-computed tomography will be used to characterize porosity and brine channel topology at 1 cm intervals along ice cores and provide quantitative data on microstructural differences in ice influenced by the freshwater. Laboratory tests and modeling will be used to examine heat transfer through sea ice cores held at their in situ temperature gradient, as a function of microstructural stratigraphy. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/90798
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| Appears in Collections: | 全球变化的国际研究计划
科学计划与规划
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| Recommended Citation: | |
Ignatius Rigor. Collaborative Research: Arctic Land Fast Sea Ice Formation in the Presence of Fresh Water Input. 2016-01-01.
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