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The Cryosphere An interactive open-access journal of the European Geosciences Union
doi:10.5194/tc-2016-130
© Author(s) 2016. This work is distributed
under the Creative Commons Attribution 3.0 License.
Research article
04 Jul 2016
Review status
A revision of this discussion paper was accepted for the journal The Cryosphere (TC) and is expected to appear here in due course.
Transient modeling of the ground thermal conditions using satellite data in the Lena River Delta, Siberia
Sebastian Westermann1, Maria Peter1,2,a, Moritz Langer3,2, Georg Schwamborn2, Lutz Schirrmeister2, Bernd Etzelmüller1, and Julia Boike2 1Department of Geosciences, University of Oslo, P.O. Box 104 7, Blindern, 0316 Oslo, Norway
2Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Telegrafenberg A43, 14473 Potsdam, Germany
3Department of Geography, Humboldt-University, Unter den Linden 6, 10099 Berlin, Germany
anow at: Université du Québec à Trois-Rivières, 3351 boul. des Forges, C.P. 500, Trois-Rivières G9A 5H7, Canada
Abstract. Permafrost is a sensitive element of the cryosphere, but operational monitoring of the ground thermal conditions on large spatial scales is still lacking. Here, we demonstrate a remote-sensing based scheme that is capable of estimating the transient evolution of ground temperatures and active layer thickness by means of the ground thermal model CryoGrid 2. The scheme is applied to an area of approx. 16 000 km2 in the Lena River Delta in NE Siberia for a period of 14 years. The forcing data sets at 1 km spatial and weekly temporal resolution are synthesized from satellite products (MODIS Land Surface Temperature, MODIS Snow Extent, GlobSnow Snow Water Equivalent) and fields of meteorological variables from the ERA-interim reanalysis. To assign spatially distributed ground thermal properties, a stratigraphic classification based on geomorphological observations and mapping is constructed which accounts for the large-scale patterns of sediment types, ground ice and surface properties in the Lena River Delta.

A comparison of the model forcing to in-situ measurements on Samoylov Island in the southern part of the study area yields a satisfactory agreement both for surface temperature, snow depth and timing of the onset and termination of the winter snow cover. The model results are compared to observations of ground temperatures and thaw depths at nine sites in in the Lena River Delta which suggests that thaw depths are in most cases reproduced to within 0.1 m or less and multi-year averages of ground temperatures within 1 to 1.5 °C. The warmest ground temperatures are calculated for grid cells close to the main river channels in the south, as well as areas with sandy sediments and low organic and ice contents in the central delta, where also the largest thaw depths occur. On the other hand, the coldest temperatures are modeled for the eastern part, an area with low surface temperatures and snow depths. The lowest thaw depths are modeled for Yedoma permafrost featuring very high ground ice and soil organic contents in the southern parts of the delta.

The comparison to in-situ observations indicates that the satellite-based model scheme is generally capable of estimating the thermal state of permafrost and its time evolution in the Lena River Delta. The approach could hence be a first step towards remote detection of ground thermal conditions and active layer thickness in permafrost areas.


Citation: Westermann, S., Peter, M., Langer, M., Schwamborn, G., Schirrmeister, L., Etzelmüller, B., and Boike, J.: Transient modeling of the ground thermal conditions using satellite data in the Lena River Delta, Siberia, The Cryosphere Discuss., doi:10.5194/tc-2016-130, in review, 2016.
Sebastian Westermann et al.
Sebastian Westermann et al.

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Short summary
We demonstrate a remote-sensing based scheme estimating the evolution of ground temperature and active layer thickness by means of a ground thermal model. A comparison to in-situ observations from the Lena River Delta in Siberia indicates that the model is generally capable of reproducing the annual temperature regime and seasonal thawing of the ground. The approach could hence be a first step towards remote detection of ground thermal conditions in permafrost areas.
We demonstrate a remote-sensing based scheme estimating the evolution of ground temperature and...
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