Atmospheric carbon dioxide and methane concentrations in the past and synchronisation of ice core records from both hemispheres based on methane results ...
In the central parts of the large polar ice sheets ice is formed by dry sintering of cold snow. The analyses of air extracted from bubbles of well dated ice samples from such locations, allow to determine the composition of the atmosphere at the time of ice formation. Of special interest are the two...
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| Format: | Text |
| Language: | unknown |
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National Institute of Polar Research
1998
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| Online Access: | https://dx.doi.org/10.48350/161140 https://boris.unibe.ch/161140/ |
| Summary: | In the central parts of the large polar ice sheets ice is formed by dry sintering of cold snow. The analyses of air extracted from bubbles of well dated ice samples from such locations, allow to determine the composition of the atmosphere at the time of ice formation. Of special interest are the two dominant greenhouse gases carbon dioxide and methane. The methane concentrations are very reproducible and represent the atmospheric concentration at the time of ice formation with a good accuracy. The records show unexpected variations of this concentration during the glacial epoch as well as during the Holocene. The concentration differences measured on ice cores from Greenland and Antarctica allow to determine concentration differences between the Northern and Southern Hemispheres. Ice core records show that the atmospheric CO_2 concentration has increased steadily from about 280 ppmv in 1750 to the present value of about 355 ppmv and that the large climatic change from the last glacial to the post glacial ... |
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