A stochastic model for the polygonal tundra based on Poisson-Voronoi diagrams
Artikel i vetenskaplig tidskrift, 2013

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.

FEEDBACKS

NORTHERN SIBERIA

ATMOSPHERE

SURFACE-ENERGY BALANCE

CLIMATE-CHANGE

NATURAL WETLANDS

DERIVE METHANE EMISSIONS

VEGETATION

WATER

ECOSYSTEMS

Författare

F. C. Aleina

Max Planck-institutet

V. Brovkin

Max Planck-institutet

S. Muster

Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung

J. Boike

Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung

L. Kutzbach

Universität Hamburg

T. Sachs

Deutsches GeoForschungsZentrum (GFZ)

Sergey Zuev

Göteborgs universitet

Chalmers, Matematiska vetenskaper, matematisk statistik

Earth System Dynamics

2190-4979 (ISSN) 2190-4987 (eISSN)

Vol. 4 187-198

Ämneskategorier

Matematik

DOI

10.5194/esd-4-187-2013