Methane emission from Siberian arctic polygonal tundra: eddy covariance measurements and modeling
Eddy covariance measurements of methane flux were carried out in an arctic tundra landscape in the central Lena River Delta at 721N. The measurements covered the seasonal course of mid-summer to early winter in 2003 and early spring to mid-summer in 2004, including the periods of spring thaw and aut...
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.598.2545 http://flux.aos.wisc.edu/twiki/pub/Main/WetlandPapers/showPdf-7.pdf |
| Summary: | Eddy covariance measurements of methane flux were carried out in an arctic tundra landscape in the central Lena River Delta at 721N. The measurements covered the seasonal course of mid-summer to early winter in 2003 and early spring to mid-summer in 2004, including the periods of spring thaw and autumnal freeze back. The study site is characterized by very cold and deep permafrost and a continental climate with a mean annual air temperature of 14.7 1C. The surface is characterized by wet polygonal tundra, with a micro-relief consisting of raised moderately dry sites, depressed wet sites, polygonal ponds, and lakes. We found relatively low fluxes of typically 30mg CH4m 2 day1 during mid-summer and identified soil temperature and near-surface atmospheric turbulence as the factors controlling methane emission. The influence of atmospheric turbulence was attributed to the high coverage of open water surfaces in the tundra. The soil thaw depth and water table position were found to have no clear effect on methane fluxes. The excess emission during spring thawwas estimated to be about 3% |
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