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| Titel |
A simple model for predicting soil temperature in snow-covered and seasonally frozen soil: model description and testing |
| VerfasserIn |
K. Rankinen, T. Karvonen, D. Butterfield |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1027-5606
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| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 8, no. 4 ; Nr. 8, no. 4, S.706-716 |
| Datensatznummer |
250005727
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| Publikation (Nr.) |
 copernicus.org/hess-8-706-2004.pdf |
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| Zusammenfassung |
| Microbial processes in soil are moisture, nutrient and temperature
dependent and, consequently, accurate calculation of soil temperature is important
for modelling nitrogen processes. Microbial activity in soil occurs even at
sub-zero temperatures so that, in northern latitudes, a method to calculate
soil temperature under snow cover and in frozen soils is required. This paper
describes a new and simple model to calculate daily values for soil temperature
at various depths in both frozen and unfrozen soils. The model requires four
parameters: average soil thermal conductivity, specific heat capacity of soil,
specific heat capacity due to freezing and thawing and an empirical snow parameter.
Precipitation, air temperature and snow depth (measured or calculated) are needed
as input variables. The proposed model was applied to five sites in different
parts of Finland representing different climates and soil types. Observed soil
temperatures at depths of 20 and 50 cm (September 1981–August 1990) were used
for model calibration. The calibrated model was then tested using observed soil
temperatures from September 1990 to August 2001. R2-values
of the calibration period varied between 0.87 and 0.96 at a depth of 20 cm and
between 0.78 and 0.97 at 50 cm. R2-values of the testing
period were between 0.87 and 0.94 at a depth of 20cm, and between 0.80 and 0.98
at 50cm. Thus, despite the simplifications made, the model was able to simulate
soil temperature at these study sites. This simple model simulates soil temperature
well in the uppermost soil layers where most of the nitrogen processes occur.
The small number of parameters required means that the model is suitable for
addition to catchment scale models.
Keywords: soil temperature, snow model |
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