Brief Communication: The reliability of gas extraction techniques for analysing CH4 and N2O compositions in gas trapped in permafrost ice wedges
International audience Methane (CH 4) and nitrous oxide (N 2 O) compositions in ground ice may provide information on their production mechanisms in permafrost. However, existing gas extraction methods have not been well tested. We tested conventional wet and dry gas extraction methods using ice wed...
Published in: | The Cryosphere |
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Main Authors: | , , , , , |
Other Authors: | , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2020
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Subjects: | |
Online Access: | https://hal.archives-ouvertes.fr/hal-02971262 https://hal.archives-ouvertes.fr/hal-02971262/document https://hal.archives-ouvertes.fr/hal-02971262/file/tc-14-1311-2020.pdf https://doi.org/10.5194/tc-14-1311-2020 |
Summary: | International audience Methane (CH 4) and nitrous oxide (N 2 O) compositions in ground ice may provide information on their production mechanisms in permafrost. However, existing gas extraction methods have not been well tested. We tested conventional wet and dry gas extraction methods using ice wedges from Alaska and Siberia, finding that both methods can extract gas from the easily extractable parts of the ice (e.g. gas bubbles) and yield similar results for CH 4 and N 2 O mixing ratios. We also found insignificant effects of microbial activity during wet extraction. However, both techniques were unable to fully extract gas from the ground ice, presumably because gas molecules adsorbed onto or enclosed in soil aggregates are not easily extractable. Estimation of gas production in a subfreezing environment of permafrost should consider such incomplete gas extraction. |
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