There exist the widely accepted wetlands hypothesis and a new hydrate gun hypothesis, for the periodic changes of atmospheric methane concentration recorded in the Antarctic and Greenland ice cores. O'Hara tried to identify the probability of methane sources between gas hydrate and wetlands by model simulations with first-order kinetics. The results suggested that it is not wetlands but gas hydrate that may be the major source of the atmospheric CH4. This paper checked the mathematical derivation and the model mechanism, then corrected the model and came up with distinguished new results. The best-fit modified model requires the methane concentration of 10 kg?m-3 for marine gas hydrates or that of 1600 kg?m-3 for wetlands. But no methane source with so high content is found in gas hydrate or wetlands. The results did not eliminate gas hydrate or wetlands as the primary CH4 source, but reflected that the model was a closed system for the CH4 source, which so needs high initial methane concentration. This model mechanism conflicts with the fact that both gas hydrates and wetlands develop as open systems.
ZHANG Hui
,
YAN Pin
. Model comparison of the effect of gas hydrates and wetlands on the atmospheric methane concentration variation in late Quaternary[J]. Journal of Tropical Oceanography, 2012
, 31(5)
: 57
-61
.
DOI: 10.11978/j.issn.1009-5470.2012.05.008
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