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High emission of carbon dioxide and methane during ice thaw in high latitude lakes
Author(s) -
Karlsson Jan,
Giesler Reiner,
Persson Jenny,
Lundin Erik
Publication year - 2013
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/grl.50152
Subject(s) - subarctic climate , environmental science , carbon dioxide , sink (geography) , flux (metallurgy) , methane , atmospheric sciences , sea ice , thermokarst , latitude , period (music) , oceanography , hydrology (agriculture) , permafrost , geology , chemistry , geography , physics , cartography , geotechnical engineering , organic chemistry , geodesy , acoustics
The winter period is seldom included in the estimates of aquatic‐atmospheric carbon exchange. In this study we quantified the flux of carbon dioxide (CO 2 ) and methane (CH 4 ) over 3 years from 12 small subarctic lakes. The lakes accumulated consistent and high amounts of CO 2 and CH 4 (56–97% as CO 2 ) over the winter, resulting in a high flux during ice thaw. The CO 2 flux during ice thaw increased with increasing mean depth of the lakes, while the CH 4 flux was high in lakes surrounded by mires. The ice thaw period was quantitatively important to the annual gas balances of the lakes. For nine of the lakes, 11 to 55% of the annual flux occurred during thaw. For three of the lakes with an apparent net annual CO 2 uptake, including the thaw period reversed the balance from sink to source. Our results suggest that the ice thaw period is critically important for the emissions of CO 2 and CH 4 in small lakes.