Carbon dioxide concentration in bubbles of natural cold ice
Carbon dioxide concentration in bubbles of natural cold ice
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天然冷冰气泡中的二氧化碳浓度
DOI：
10.1021/j100244a025
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发表时间：
1983
期刊：
影响因子：
--
通讯作者：
B. Stauffer
中科院分区：
文献类型：
--
作者：
A. Neftel;H. Oeschger;J. Schwander;B. Stauffer
由于周围冰的静水压力，冰盖中的气泡压力随着深度而增加。在低于一定深度（取决于冰温）时，由于空气包合物的形成，气泡的收缩速度比预期的要快。在冰芯从该深度以下恢复和减压后，新的气泡再次开始形成。一年内，大部分空气再次聚集在新形成的气泡中。我们通过红外激光光谱仪测量了在 -20/sup 0/C 下通过机械粉碎小冰样品提取的气体中的 CO/sub 2/ 浓度。我们分析了最近钻探的 Dye 3 岩心（南格陵兰岛）地表以下 1600 米深度、开采后几天、几周和几个月的样本。这使我们能够研究包合物形成和不完全反向扩散对测量的 CO/sub 2/ 浓度的影响。 CO/sub 2/ 包合物的形成和反向扩散过程当然受到CO/sub 2/ 在冰结构中的溶解度的影响。我们实验室发布的早期测量结果高估了这种溶解度。对实验室生长的单晶中 CO/sub 2/ 浓度的新测量可以更好地估计 CO/sub 2/ 在冰中的溶解度。根据 Dye 3 岩心冰样本测量的 CO/sub 2/ 浓度的季节性变化，我们可以估计 -20/sup 0/C 时天然多晶冰中 CO/sub 2/ 扩散常数的上限。 6 位数字。« 更少
The bubble pressure in an ice sheet is increasing with depth, due to the hydrostatic pressure of the surrounding ice. Below a certain depth, which depends on the ice temperature, bubbles are shrinking faster than expected, due to formation of air clathrates. After recovery and decompression of ice cores from below this depth, new bubbles start to form again. Within 1 year most of the air is collected again in newly formed bubbles. We measured by means of an infrared laser spectrometer the CO/sub 2/ concentration in gas extracted by mechanically crushing small ice samples at -20/sup 0/C. We analyzed samples from a depth of 1600 m below surface from the recently drilled Dye 3 core (South Greenland), a few days, a few weeks, and a few months after recovery. This allows us to investigate the influence of clathrate formation and incomplete back-diffusion to the measured CO/sub 2/ concentration. The formation of CO/sub 2/ clathrates and the back-diffusion process is certainly influenced by the solubility of CO/sub 2/ in the ice structure. Earlier measurements published by our laboratory overestimated this solubility. New measurements of the CO/sub 2/ concentration in laboratory grown single crystals allow a better estimate of the solubilitymore » of CO/sub 2/ in ice. The seasonal variations of the CO/sub 2/ concentration measured on ice samples from the Dye 3 core allow us to estimate an upper limit for the diffusion constant of CO/sub 2/ in natural polycrystalline ice at -20/sup 0/C. 6 figures.« less