LCC Network Data Steward(Point of Contact), Arctic Landscape Conservation Cooperative(administrator), 2015-11-02(lastUpdate), 2011-09-28(Publication), Mean Annual Ground Temperature 2030-2039, https://www.fws.gov/science/catalog, https://www.sciencebase.gov/catalog/item/5a300b14e4b08e6a89d57cc2
Summary
This raster, created in 2010, is output from the Geophysical Institute Permafrost Lab (GIPL) model and represents simulated mean annual ground temperature (MAGT) in Celsius, averaged across a decade, at the base of active layer or at the base of the seasonally frozen soil column. The file name specifies the decade the raster represents. For example, a file named MAGT_1980_1989.tif represents the decade spanning 1980-1989. Cell values represent simulated mean annual ground temperature (degree C) at the base of the active layer (for areas with permafrost) or at the base of the soil column that is seasonally frozen (for areas without permafrost). If the value of the cell is negative,the area has permafrost and the cell value specifies [...]
Summary
This raster, created in 2010, is output from the Geophysical Institute Permafrost Lab (GIPL) model and represents simulated mean annual ground temperature (MAGT) in Celsius, averaged across a decade, at the base of active layer or at the base of the seasonally frozen soil column. The file name specifies the decade the raster represents. For example, a file named MAGT_1980_1989.tif represents the decade spanning 1980-1989. Cell values represent simulated mean annual ground temperature (degree C) at the base of the active layer (for areas with permafrost) or at the base of the soil column that is seasonally frozen (for areas without permafrost). If the value of the cell is negative,the area has permafrost and the cell value specifies MAGT at the base of the active layer. If the value of the cell is positive, the ground is only seasonally frozen and the cell value specifies MAGT at the base of seasonal frost. The raster covers the entire state of Alaska and has a spatial resolution of 2 x 2km. These data were generated by forcing the GIPL model with a composite of five GCM model outputs (ECHAM5, GFLD21, MIROC, HADLEY and CCCMA) for the A1B emissions scenario.
The Geophysical Institute Permafrost Lab (GIPL) model was developed specifically to assess the effect of a changing climate on permafrost. The GIPL-1 model is a quasi-transitional, spatially distributed, equilibrium model for calculating the active layer thickness and mean annual ground temperature. The GIPL-1 model accounts effectively for the effects of snow cover, vegetation, soil moisture, and soil thermal properties. The GIPL-1 model allows for the calculation of maximum active layer thickness (ALT) and mean annual ground temperatures (MAGT) at the bottom of the active layer. The approach to determine the ALT and MAGT is based on an approximate analytical solution that includes freezing/thawing processes and provides an estimation of thermal offset due to the difference in frozen and thawed soil thermal properties (Kudryavtsev, et al., 1974). It uses the idea of applying the Fourier temperature wave propagation theory to a medium with phase transitions, such as freezing/thawing ground. Application of this approach resulted in the discovery of the thermal offset and an understanding of the laws that govern the dynamics of the ground thermal regime. These discoveries led to an understanding of the effects that the thermal properties of the ground have upon the MAGTs and ALT, and how periodically (seasonally) varying climatic parameters affect permafrost dynamics. The output parameters of this method are given as annual averages.
