Physical controls on the storage of methane in landfast sea ice
Physical controls on the storage of methane in landfast sea ice
复制标题
对陆地海冰中甲烷储存的物理控制
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
B. Delille
中科院分区：
文献类型：
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作者：
Jia;J. Tison;G. Carnat;Nicolas;B. Delille
2009年，我们在巴罗的陆上快速海冰、卤水和冰下海水中报告了甲烷(CH4)的动态。冰下水中甲烷浓度变化范围为25.9nmolCH4~116.4 nmolCH4，表明相对于大气的过饱和度为700%~3100%。相比之下，海冰中的甲烷浓度范围为3.4~17.2nmol L 1号冰，而卤水中的甲烷浓度范围为13.2~677.7 nmol L 1号卤水。我们研究了导致海冰、卤水和冰下水中甲烷浓度差异的过程，并认为与物理对照相比，生物控制在冰中储存甲烷的作用较小。两个物理过程控制着我们陆地冰样中CH4的储存：冰内气泡的形成和海冰的渗透性。卤水浓度和溶解度降低所形成的气泡有利于冰生长初期甲烷在冰中的积累。当时，甲烷在海冰中的滞留效率是盐的两倍；这也解释了盐水中的甲烷浓度总体上高于冰下水中的原因。随着海冰的增厚，气泡的形成效率降低，甲烷主要被困在溶解状态。海冰融化过程中海冰渗透率的增加标志着甲烷储存的结束。
We report on methane (CH4) dynamics in land- fast sea ice, brine and under-ice seawater at Barrow in 2009. The CH4 concentrations in under-ice water ranged from 25.9 to 116.4 nmol L 1 sw , indicating a supersaturation of 700 to 3100 % relative to the atmosphere. In comparison, the CH4 concentrations in sea ice ranged from 3.4 to 17.2 nmol L 1 ice and the deduced CH4 concentrations in brine from 13.2 to 677.7 nmol L 1 brine . We investigated the processes underlying the difference in CH4 concentrations between sea ice, brine and under-ice water and suggest that biological controls on the storage of CH4 in ice were minor in comparison to the physical controls. Two physical processes regulated the stor- age of CH4 in our landfast ice samples: bubble formation within the ice and sea ice permeability. Gas bubble formation due to brine concentration and solubility decrease favoured the accumulation of CH4 in the ice at the beginning of ice growth. CH4 retention in sea ice was then twice as efficient as that of salt; this also explains the overall higher CH 4 con- centrations in brine than in the under-ice water. As sea ice thickened, gas bubble formation became less efficient, CH 4 was then mainly trapped in the dissolved state. The increase of sea ice permeability during ice melt marked the end of CH4 storage.
影响因子：
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作者：
Nicolas-Xavier Geilfus;G. Carnat;G. Dieckmann;N. Halden;G. Nehrke;T. Papakyriakou;J. Tison;B. Delille
通讯作者：
Nicolas-Xavier Geilfus;G. Carnat;G. Dieckmann;N. Halden;G. Nehrke;T. Papakyriakou;J. Tison;B. Delille