Processes affecting the CO2 concentrations measured in Greenland ice
Processes affecting the CO2 concentrations measured in Greenland ice
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影响格陵兰冰中测量的二氧化碳浓度的过程
DOI：
10.3402/tellusb.v47i4.16061
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发表时间：
1995
期刊：
影响因子：
2.3
通讯作者：
D. Raynaud
中科院分区：
文献类型：
--
作者：
M. Anklin;J. Barnola;J. Schwander;B. Stauffer;D. Raynaud
对格陵兰岛和南极洲冰芯的详细二氧化碳测量表明，在相同气体年龄的样品中，二氧化碳的平均浓度不同。在过去的一千年里，南极和格陵兰岛的二氧化碳记录之间的偏差上升到了20ppmv。根据目前对全球碳循环的了解，我们可以排除南北高纬度地区之间如此高的二氧化碳浓度半球间平均差异。公司内空气的扩散混合使大气CO 2浓度的短期变化趋于平缓。然而，我们观察到格陵兰冰的短期CO 2变化在10-20 ppmv范围内，这不能代表大气CO 2的变化。由于峰顶的低温，大多数冰可以排除融化层，它们不能解释格陵兰冰中频繁的异常短期二氧化碳变化和平均二氧化碳浓度升高。在这项工作中，我们提供了一些线索，格陵兰冰的原位二氧化碳生产可以在孔隙关闭后积累多余的二氧化碳。可能的化学反应是有机碳的氧化和酸度与碳酸盐之间的反应。我们得出结论，碳酸-酸性反应是最可能解释气泡中过量二氧化碳的过程。这种反应可以在冰冷的冰中非常小的液体状静脉中发生，在那里杂质的迁移率比在冰格中要高。目前，还没有直接测量冰中碳酸盐浓度的技术。然而，用干法和湿法提取技术进行的二氧化碳分析比较，可以估计出冰的碳酸盐含量。这一估计表明，格陵兰冰的碳酸盐浓度约为0.4±0.2µmol/l，而南极冰的浓度要低得多。DOI: 10.1034 / j.1600-0889.47.issue4.6.x
Detailed CO 2 measurements on ice cores from Greenland and Antarctica show different mean CO 2 concentrations for samples at the same gas age. The deviation between Antarctic and Greenland CO 2 records raises up to 20 ppmv during the last millennium. Based on the present knowledge of the global carbon cycle we can exclude such a high mean interhemispheric difference of the CO 2 concentration between high northern and southern latitudes. Diffusive mixing of the air in the firn smoothes out short term variations of the atmospheric CO 2 Concentration. Nevertheless, we observe short term CO 2 variations in Greenland ice in the range of 10–20 ppmv, which cannot represent atmospheric CO 2 variations. Due to the low temperature at Summit, meltlayers can be excluded for most of the ice and they cannot account for the frequent anomalous short term CO 2 variations and the elevated mean CO 2 concentration in the Greenland ice. In this work we give some clues, that in situ production of CO 2 in Greenland ice could build up excess CO 2 after pore close of. Possible chemical reactions are the oxidation of organic carbon and the reaction between acidity and carbonate. We conclude that the carbonate-acidity reaction is the most probable process to explain the excess CO 2 in the bubbles. The reaction could take place in very small liquid-like veins in cold ice, where the mobility of impurities is higher than in the ice lattice. At present, there exists no technique to measure the carbonate concentration in the ice directly. However, a comparison of CO 2 analyses performed with a dry- and a wet-extraction technique allows to estimate the carbonate content of the ice. This estimate indicates a carbonate concentration in Greenland ice of about 0.4 ± 0.2 µ mol/l and a much lower concentration in Antarctic ice. DOI: 10.1034/j.1600-0889.47.issue4.6.x