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Titel |
Freeze/thaw processes in complex permafrost landscapes of northern Siberia simulated using the TEM ecosystem model: impact of thermokarst ponds and lakes |
VerfasserIn |
S. YI, K. Wischnewski, M. Langer, S. Muster, J. Boike |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1991-959X
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Digitales Dokument |
URL |
Erschienen |
In: Geoscientific Model Development ; 7, no. 4 ; Nr. 7, no. 4 (2014-08-15), S.1671-1689 |
Datensatznummer |
250115678
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Publikation (Nr.) |
copernicus.org/gmd-7-1671-2014.pdf |
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Zusammenfassung |
Freeze/thaw (F/T) processes can be quite different under the various land
surface types found in the complex tundra of the Arctic, such as polygonal
tundra (wet center and dry rims), ponds, and thermokarst lakes. Proper
simulation of these different processes is essential for accurate prediction
of the release of greenhouse gases under a warming climate scenario. In this
study we have incorporated the water layer into a dynamic organic soil
version of the Terrestrial Ecosystem Model (DOS-TEM), having first verified
and validated the model. Results showed that (1) the DOS-TEM was very
efficient and its results compared well with analytical solutions for
idealized cases, and (2) despite a number of limitations and uncertainties
in the modeling, the simulations compared reasonably well with in situ measurements
from polygon rims, polygon centers (with and without water), and lakes on
Samoylov Island, Siberia, indicating the suitability of the DOS-TEM for
simulating the various F/T processes. Sensitivity tests were performed on
the effects of water depth and our results indicated that both water and
snow cover are very important in the simulated thermal processes, for both
polygon centers and lakes. We therefore concluded that the polygon rims and
polygon centers (with various maximum water depths) should be considered
separately, and that the dynamics of water depth in both polygons and lakes
should be taken into account when simulating thermal processes for methane
emission studies. |
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