Frozen ponds: production and storage of methane during the Arctic winter in a lowland tundra landscape in northern Siberia, Lena River delta
Lakes and ponds play a key role in the carbon cycle of permafrost ecosystems, where they are considered to be hotspots of carbon dioxide CO<sub>2</sub> and methane CH<sub>4</sub> emission. The strength of these emissions is, however, controlled by a variety of physical and bi...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2015-02-01
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| Series: | Biogeosciences |
| Online Access: | http://www.biogeosciences.net/12/977/2015/bg-12-977-2015.pdf |
| _version_ | 1828156121304530944 |
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| author | M. Langer S. Westermann K. Walter Anthony K. Wischnewski J. Boike |
| author_facet | M. Langer S. Westermann K. Walter Anthony K. Wischnewski J. Boike |
| author_sort | M. Langer |
| collection | DOAJ |
| description | Lakes and ponds play a key role in the carbon cycle of permafrost ecosystems,
where they are considered to be hotspots of carbon dioxide CO<sub>2</sub> and
methane CH<sub>4</sub> emission. The strength of these emissions is, however,
controlled by a variety of physical and biogeochemical processes whose
responses to a warming climate are complex and only poorly understood. Small
waterbodies have been attracting an increasing amount of attention since
recent studies demonstrated that ponds can make a significant contribution to
the CO<sub>2</sub> and CH<sub>4</sub>emissions of tundra ecosystems. Waterbodies
also have a marked effect on the thermal state of the surrounding permafrost;
during the freezing period they prolong the period of time during which
thawed soil material is available for microbial decomposition.
<br><br>
This study presents net CH<sub>4</sub> production rates during the freezing
period from ponds within a typical lowland tundra landscape in northern
Siberia. Rate estimations were based on CH<sub>4</sub> concentrations measured
in surface lake ice from a variety of waterbody types. Vertical profiles
along ice blocks showed an exponential increase in CH<sub>4</sub> concentration
with depth. These CH<sub>4</sub> profiles were reproduced by a 1-D mass balance
model and the net CH<sub>4</sub> production rates were then inferred through
inverse modeling.
<br><br>
Results revealed marked differences in early winter net CH<sub>4</sub>
production among various ponds. Ponds situated within intact polygonal ground
structures yielded low net production rates, of the order of 10<sup>-11</sup> to
10<sup>-10</sup> mol m<sup>-2</sup> s<sup>-1</sup> (0.01 to 0.14 mg<sub>CH<sub>4</sub></sub> m<sup>-2</sup> day<sup>-1</sup>). In contrast, ponds exhibiting
clear signs of erosion yielded net CH<sub>4</sub> production rates of the order
of 10<sup>-7</sup> mol m<sup>-2</sup> s<sup>-1</sup> (140 mg <sub>CH<sub>4</sub></sub> m<sup>-2</sup> day<sup>-1</sup>). Our
results therefore indicate that once a particular threshold in thermal
erosion has been crossed, ponds can develop into major CH<sub>4</sub> sources.
This implies that any future warming of the climate may result in nonlinear
CH<sub>4</sub> emission behavior in tundra ecosystems. |
| first_indexed | 2024-04-11T23:05:23Z |
| format | Article |
| id | doaj.art-6256622ef20d47b8b310f73903fcd61e |
| institution | Directory Open Access Journal |
| issn | 1726-4170 1726-4189 |
| language | English |
| last_indexed | 2024-04-11T23:05:23Z |
| publishDate | 2015-02-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Biogeosciences |
| spelling | doaj.art-6256622ef20d47b8b310f73903fcd61e2022-12-22T03:58:02ZengCopernicus PublicationsBiogeosciences1726-41701726-41892015-02-0112497799010.5194/bg-12-977-2015Frozen ponds: production and storage of methane during the Arctic winter in a lowland tundra landscape in northern Siberia, Lena River deltaM. Langer0S. Westermann1K. Walter Anthony2K. Wischnewski3J. Boike4Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Periglacial Research Section, Potsdam, GermanyDepartment of Geography, University of Oslo, Oslo, NorwayUniversity of Alaska Fairbanks, Water and Environmental Research Center, Fairbanks, USAAlfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Periglacial Research Section, Potsdam, GermanyAlfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Periglacial Research Section, Potsdam, GermanyLakes and ponds play a key role in the carbon cycle of permafrost ecosystems, where they are considered to be hotspots of carbon dioxide CO<sub>2</sub> and methane CH<sub>4</sub> emission. The strength of these emissions is, however, controlled by a variety of physical and biogeochemical processes whose responses to a warming climate are complex and only poorly understood. Small waterbodies have been attracting an increasing amount of attention since recent studies demonstrated that ponds can make a significant contribution to the CO<sub>2</sub> and CH<sub>4</sub>emissions of tundra ecosystems. Waterbodies also have a marked effect on the thermal state of the surrounding permafrost; during the freezing period they prolong the period of time during which thawed soil material is available for microbial decomposition. <br><br> This study presents net CH<sub>4</sub> production rates during the freezing period from ponds within a typical lowland tundra landscape in northern Siberia. Rate estimations were based on CH<sub>4</sub> concentrations measured in surface lake ice from a variety of waterbody types. Vertical profiles along ice blocks showed an exponential increase in CH<sub>4</sub> concentration with depth. These CH<sub>4</sub> profiles were reproduced by a 1-D mass balance model and the net CH<sub>4</sub> production rates were then inferred through inverse modeling. <br><br> Results revealed marked differences in early winter net CH<sub>4</sub> production among various ponds. Ponds situated within intact polygonal ground structures yielded low net production rates, of the order of 10<sup>-11</sup> to 10<sup>-10</sup> mol m<sup>-2</sup> s<sup>-1</sup> (0.01 to 0.14 mg<sub>CH<sub>4</sub></sub> m<sup>-2</sup> day<sup>-1</sup>). In contrast, ponds exhibiting clear signs of erosion yielded net CH<sub>4</sub> production rates of the order of 10<sup>-7</sup> mol m<sup>-2</sup> s<sup>-1</sup> (140 mg <sub>CH<sub>4</sub></sub> m<sup>-2</sup> day<sup>-1</sup>). Our results therefore indicate that once a particular threshold in thermal erosion has been crossed, ponds can develop into major CH<sub>4</sub> sources. This implies that any future warming of the climate may result in nonlinear CH<sub>4</sub> emission behavior in tundra ecosystems.http://www.biogeosciences.net/12/977/2015/bg-12-977-2015.pdf |
| spellingShingle | M. Langer S. Westermann K. Walter Anthony K. Wischnewski J. Boike Frozen ponds: production and storage of methane during the Arctic winter in a lowland tundra landscape in northern Siberia, Lena River delta Biogeosciences |
| title | Frozen ponds: production and storage of methane during the Arctic winter in a lowland tundra landscape in northern Siberia, Lena River delta |
| title_full | Frozen ponds: production and storage of methane during the Arctic winter in a lowland tundra landscape in northern Siberia, Lena River delta |
| title_fullStr | Frozen ponds: production and storage of methane during the Arctic winter in a lowland tundra landscape in northern Siberia, Lena River delta |
| title_full_unstemmed | Frozen ponds: production and storage of methane during the Arctic winter in a lowland tundra landscape in northern Siberia, Lena River delta |
| title_short | Frozen ponds: production and storage of methane during the Arctic winter in a lowland tundra landscape in northern Siberia, Lena River delta |
| title_sort | frozen ponds production and storage of methane during the arctic winter in a lowland tundra landscape in northern siberia lena river delta |
| url | http://www.biogeosciences.net/12/977/2015/bg-12-977-2015.pdf |
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