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| Titel |
A stochastic model for the polygonal tundra based on Poisson–Voronoi diagrams |
| VerfasserIn |
F. Cresto Aleina, V. Brovkin, S. Muster, J. Boike, L. Kutzbach, T. Sachs, S. Zuyev |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
2190-4979
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| Digitales Dokument |
URL |
| Erschienen |
In: Earth System Dynamics ; 4, no. 2 ; Nr. 4, no. 2 (2013-07-11), S.187-198 |
| Datensatznummer |
250017785
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| Publikation (Nr.) |
 copernicus.org/esd-4-187-2013.pdf |
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| Zusammenfassung |
| Subgrid processes occur in various ecosystems and landscapes but, because of
their small scale, they are not represented or poorly parameterized in
climate models. These local heterogeneities are often important or even
fundamental for energy and carbon balances. This is especially true for
northern peatlands and in particular for the polygonal tundra, where methane
emissions are strongly influenced by spatial soil heterogeneities. We present
a stochastic model for the surface topography of polygonal tundra using
Poisson–Voronoi diagrams and we compare the results with available recent
field studies. We analyze seasonal dynamics of water table variations and the
landscape response under different scenarios of precipitation income. We
upscale methane fluxes by using a simple idealized model for methane
emission. Hydraulic interconnectivities and large-scale drainage may also be
investigated through percolation properties and thresholds in the Voronoi
graph. The model captures the main statistical characteristics of the
landscape topography, such as polygon area and surface properties as well as
the water balance. This approach enables us to statistically relate
large-scale properties of the system to the main small-scale processes within
the single polygons. |
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