| DOI: | 10.1002/2017JC012999
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| Scopus记录号: | 2-s2.0-85042216383
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| 论文题名: | Brine Convection, Temperature Fluctuations, and Permeability in Winter Antarctic Land-Fast Sea Ice |
| 作者: | Wongpan P.; Hughes K.G.; Langhorne P.J.; Smith I.J.
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| 刊名: | Journal of Geophysical Research: Oceans
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| ISSN: | 21699275
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| 出版年: | 2018
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| 卷: | 123, 期:1 | | 起始页码: | 216
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| 结束页码: | 230
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| 语种: | 英语
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| 英文关键词: | Antarctic sea ice
; brine convection
; mushy layer
; permeability
; platelet ice
; temperature fluctuations
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| Scopus关键词: | brine
; convection
; heat flow
; ice cover
; ice-ocean interaction
; insolation
; interface
; nutrient dynamics
; permeability
; sea ice
; smoothing
; temperature effect
; temperature profile
; Antarctic Ice Sheet
; Antarctica
; East Antarctica
; McMurdo Sound
; algae
; Calluna vulgaris
|
| 英文摘要: | Vertical temperature strings are used in sea ice research to study heat flow, ice growth rate, and ocean-ice-atmosphere interaction. We demonstrate the feasibility of using temperature fluctuations as a proxy for fluid movement, a key process for supplying nutrients to Antarctic sea ice algal communities. Four strings were deployed in growing, land-fast sea ice in McMurdo Sound, Antarctica. By smoothing temperature data with the robust LOESS method, we obtain temperature fluctuations that cannot be explained by insolation or atmospheric heat loss. Statistical distributions of these temperature fluctuations are investigated with sensitivities to the distance from the ice-ocean interface, average ice temperature, and sea ice structure. Fluctuations are greatest close to the base (<50 mm) at temperatures >−3°C, and are discrete events with an average active period of 43% compared to 11% when the ice is colder (–3°C to −5°C). Assuming fluctuations occur when the Rayleigh number, derived from mushy layer theory, exceeds a critical value of 10 we approximate the harmonic mean permeability of this thick (>1 m) sea ice in terms of distance from the ice-ocean interface. Near the base, we obtain values in the same range as those measured by others in Arctic spring and summer. The permeability between the ice-ocean interface and 0.05 ± 0.04 m above it is of order 10−9 m2. Columnar and incorporated platelet ice permeability distributions in the bottom 0.1 m of winter Antarctic sea ice are statistically significantly different although their arithmetic means are indistinguishable. © 2017. American Geophysical Union. All Rights Reserved. |
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| 资源类型: | 期刊论文
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/114820
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| Appears in Collections: | 气候减缓与适应
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作者单位: | Department of Physics, University of Otago, Dunedin, New Zealand; School of Earth and Ocean Sciences, University of Victoria, Victoria, BC, Canada
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| Recommended Citation: | |
Wongpan P.,Hughes K.G.,Langhorne P.J.,et al. Brine Convection, Temperature Fluctuations, and Permeability in Winter Antarctic Land-Fast Sea Ice[J]. Journal of Geophysical Research: Oceans,2018-01-01,123(1)
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