This raster, created in 2010, is output from the Geophysical Institute Permafrost Lab (GIPL) model and represents simulated active layer thickness (ALT) in meters averaged across a decade. The file name specifies the decade the raster represents. For example, a file named ALT_1980_1989.tif represents the decade spanning 1980-1989. Cell values represent simulated maximum depth (in meters) of thaw penetration (for areas with permafrost) or frost penetration (for areas without permafrost). If the value of the cell is positive, the area is underlain by permafrost and the cell value specifies the depth of the seasonally thawing layer above permafrost. If the value of the cell is negative, the ground is only seasonally frozen and the cell value specifies the depth 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.
