CryoGRID 1.0: Permafrost Distribution in Norway estimated by a Spatial Numerical Model

CryoGRID 1.0 provides an equilibrium model of permafrost distribution in Norway at a spatial resolution of 1 km2. The approach was forced with gridded data on daily air temperature and snow cover. Ground thermal properties for different bedrock types and sediment covers were derived from surveys and geological maps to yield distributions of thermal conductivity, heat capacity and water content. The distribution of blockfields was derived from satellite images adapting a newly developed classification scheme. The model was evaluated using measured ground surface and ground temperatures, yielding a realistic description of the permafrost distribution in mainland Norway. The model results show that permafrost underlies sites mainly with exposed bedrock or covered by coarse‐grained sediments, such as blockfields and coarse tills. In northern Norway, palsa mires are abundant and organic material and vegetation strongly influence the ground thermal regime. Modelling suggests that permafrost in equilibrium with the 1981–2010 climate presently underlies between 6.1 per cent and 6.4 per cent of the total area of mainland Norway, an area significantly smaller than that modelled for the Little Ice Age climate (14%). CryoGRID 1.0 was subsequently forced using output from a regional climate model for the 2071–2100 period, which suggests that severe permafrost degradation will occur, leaving permafrost beneath an area of just 0.2 per cent of mainland Norway. Copyright © 2013 John Wiley & Sons, Ltd.