Journal cover Journal topic
The Cryosphere An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 4.524 IF 4.524
  • IF 5-year value: 5.558 IF 5-year 5.558
  • CiteScore value: 4.84 CiteScore 4.84
  • SNIP value: 1.425 SNIP 1.425
  • SJR value: 3.034 SJR 3.034
  • IPP value: 4.65 IPP 4.65
  • h5-index value: 52 h5-index 52
  • Scimago H index value: 55 Scimago H index 55
Volume 12, issue 11
The Cryosphere, 12, 3693-3717, 2018
https://doi.org/10.5194/tc-12-3693-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.

Special issue: Changing Permafrost in the Arctic and its Global Effects in...

The Cryosphere, 12, 3693-3717, 2018
https://doi.org/10.5194/tc-12-3693-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.

Research article 27 Nov 2018

Research article | 27 Nov 2018

Observation and modelling of snow at a polygonal tundra permafrost site: spatial variability and thermal implications

Isabelle Gouttevin1,2,a, Moritz Langer3,4, Henning Löwe5, Julia Boike3,4, Martin Proksch5, and Martin Schneebeli5 Isabelle Gouttevin et al.
  • 1Irstea, UR HHLY, Centre de Lyon-Villeurbanne, 5 Rue de la Doua, BP 32108, 69616 Villeurbanne CEDEX, France
  • 2Université Grenoble Alpes, Irstea, UR ETGR, Centre de Grenoble, 2 rue de la Papeterie-BP 76, 38402 St-Martin-d'Hères, France
  • 3Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research (AWI), Telegrafenberg A6, 14473 Potsdam, Germany
  • 4Department of Geography, Humboldt-Universität zu Berlin, Rudower Chaussee 16, 12489 Berlin, Germany
  • 5WSL Institute for Snow and Avalanche Research SLF, Flueelastr. 11, 7260 Davos Dorf, Switzerland
  • anow at: Univ. Grenoble Alpes, Université de Toulouse, Météo-France, CNRS, CNRM, Centre d'Etudes de la Neige, Grenoble, France

Abstract. The shortage of information on snow properties in high latitudes places a major limitation on permafrost and more generally climate modelling. A dedicated field program was therefore carried out to investigate snow properties and their spatial variability at a polygonal tundra permafrost site. Notably, snow samples were analysed for surface-normal thermal conductivity (Keff − z) based on X-ray microtomography. Also, the detailed snow model SNOWPACK was adapted to these Arctic conditions to enable relevant simulations of the ground thermal regime. Finally, the sensitivity of soil temperatures to snow spatial variability was analysed.

Within a typical tundra snowpack composed of depth hoar overlain by wind slabs, depth hoar samples were found more conductive (Keff − z = 0.22±0.05Wm−1K−1) than in most previously published studies, which could be explained by their high density and microstructural anisotropy. Spatial variations in the thermal properties of the snowpack were well explained by the microtopography and ground surface conditions of the polygonal tundra, which control depth hoar growth and snow accumulation. Our adaptations to SNOWPACK, phenomenologically taking into account the effects of wind compaction, basal vegetation, and water vapour flux, yielded realistic density and Keff − z profiles that greatly improved simulations of the ground thermal regime. Also, a density- and anisotropy-based parameterization for Keff − z lead to further slight improvements. Soil temperatures were found to be particularly sensitive to snow conditions during the early winter and polar night, highlighting the need for improved snow characterization and modelling over this period.

Publications Copernicus
Special issue
Download
Short summary
Snow insulates the ground from the cold air in the Arctic winter, majorly affecting permafrost. This insulation depends on snow characteristics and is poorly quantified. Here, we characterize it at a carbon-rich permafrost site, using a recent technique that retrieves the 3-D structure of snow and its thermal properties. We adapt a snowpack model enabling the simulation of this insulation over a whole winter. We estimate that local snow variations induce up to a 6 °C spread in soil temperatures.
Snow insulates the ground from the cold air in the Arctic winter, majorly affecting permafrost....
Citation
Share