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| Titel |
Numerical modeling of permafrost dynamics in Alaska using a high spatial resolution dataset |
| VerfasserIn |
E. E. Jafarov, S. S. Marchenko, V. E. Romanovsky |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1994-0416
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| Digitales Dokument |
URL |
| Erschienen |
In: The Cryosphere ; 6, no. 3 ; Nr. 6, no. 3 (2012-06-04), S.613-624 |
| Datensatznummer |
250003595
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| Publikation (Nr.) |
 copernicus.org/tc-6-613-2012.pdf |
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| Zusammenfassung |
Climate projections for the 21st century indicate that there could be a
pronounced warming and permafrost degradation in the Arctic and sub-Arctic
regions. Climate warming is likely to cause permafrost thawing with
subsequent effects on surface albedo, hydrology, soil organic matter storage
and greenhouse gas emissions.
To assess possible changes in the permafrost thermal state and active layer
thickness, we implemented the GIPL2-MPI transient numerical model for the
entire Alaska permafrost domain. The model input parameters are spatial
datasets of mean monthly air temperature and precipitation, prescribed
thermal properties
of the multilayered soil column, and water content that are specific for each soil class and geographical location. As a climate forcing, we used the
composite of five IPCC Global Circulation Models that has been downscaled to
2 by 2 km spatial resolution by Scenarios Network for Alaska Planning (SNAP)
group.
In this paper, we present the modeling results based on input of a five-model
composite with A1B carbon emission scenario. The model has been calibrated
according to the annual borehole temperature measurements for the State of
Alaska. We also performed more detailed calibration for fifteen shallow
borehole stations where high quality data are available on daily basis. To
validate the model performance, we compared simulated active layer
thicknesses with observed data from Circumpolar Active Layer Monitoring
(CALM) stations. The calibrated model was used to address possible ground
temperature changes for the 21st century. The model simulation results show
widespread permafrost degradation in Alaska could begin between 2040–2099
within the vast area southward from the Brooks Range, except for the high
altitude regions of the Alaska Range and Wrangell Mountains. |
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