DOI: 10.5194/tc-8-1469-2014
Scopus记录号: 2-s2.0-84920725177
论文题名: Temporal dynamics of ikaite in experimental sea ice
作者: Rysgaard S ; , Wang F ; , Galley R ; J ; , Grimm R ; , Notz D ; , Lemes M ; , Geilfus N ; -X ; , Chaulk A ; , Hare A ; A ; , Crabeck O ; , Else B ; G ; T ; , Campbell K ; , Sørensen L ; L ; , Sievers J ; , Papakyriakou T
刊名: Cryosphere
ISSN: 19940416
出版年: 2014
卷: 8, 期: 4 起始页码: 1469
结束页码: 1478
语种: 英语
英文关键词: air-sea interaction
; calcium carbonate
; carbon dioxide
; high pressure
; ikaite
; sea ice
; snow cover
; spatiotemporal analysis
; Canada
; Manitoba
英文摘要: Ikaite (CaCO3 · 6H2 O) is a metastable phase of calcium carbonate that normally forms in a cold environment and/or under high pressure. Recently, ikaite crystals have been found in sea ice, and it has been suggested that their precipitation may play an important role in air-sea CO 2 exchange in ice-covered seas. Little is known, however, of the spatial and temporal dynamics of ikaite in sea ice. Here we present evidence for highly dynamic ikaite precipitation and dissolution in sea ice grown at an outdoor pool of the Sea-ice Environmental Research Facility (SERF) in Manitoba, Canada. During the experiment, ikaite precipitated in sea ice when temperatures were below -4 °C, creating three distinct zones of ikaite concentrations: (1) a millimeter-to-centimeter-thin surface layer containing frost flowers and brine skim with bulk ikaite concentrations of >2000 μmol kg-1, (2) an internal layer with ikaite concentrations of 200-400 μmol kg -1, and (3) a bottom layer with ikaite concentrations of <100 μmol kg-1. Snowfall events caused the sea ice to warm and ikaite crystals to dissolve. Manual removal of the snow cover allowed the sea ice to cool and brine salinities to increase, resulting in rapid ikaite precipitation. The observed ikaite concentrations were on the same order of magnitude as modeled by FREZCHEM, which further supports the notion that ikaite concentration in sea ice increases with decreasing temperature. Thus, varying snow conditions may play a key role in ikaite precipitation and dissolution in sea ice. This could have a major implication for CO2 exchange with the atmosphere and ocean that has not been accounted for previously. © Author(s) 2014. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/74807
Appears in Collections: 影响、适应和脆弱性 气候变化与战略
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作者单位: Centre for Earth Observation Science, Department of Environment and Geography, University of Manitoba, Winnipeg, MB R3T 2N2, Canada; Department of Geological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada; Greenland Climate Research Centre, Greenland Institute of Natural Resources, 3900 Nuuk, Greenland; Arctic Research Centre, Aarhus University, 8000 Aarhus, Denmark; Department of Chemistry, University of Manitoba, Winnipeg, MB R3T 2N2, Canada; Max Planck Institute for Meteorology, Hamburg, Germany; Aarhus University, Department of Environmental Science, 4000 Roskilde, Denmark
Recommended Citation:
Rysgaard S,, Wang F,, Galley R,et al. Temporal dynamics of ikaite in experimental sea ice[J]. Cryosphere,2014-01-01,8(4)