There is ample evidence which now indicates that the global climate is warming. To investigate the effects of climate change on the thermal processes in arctic tundra, a one-dimensional heat conduction model has been developed. The model was formulated using a finite element technique and includes the effects of phase change and variable properties. A surface energy balance model has been coupled with the heat conduction model to solve the one-dimensional heat transfer problem within the active layer and permafrost. Equations representing the interacting processes of the surface energy balance are solved simultaneously for the surface temperature which is then used to drive the sub-surface heat conduction model. This model simulates the sub-surface temperature and depth of thaw.
A spatially distributed model was designed to calculate the surface and subsurface temperature and thaw depth on a grid encompassing the Kuparuk River basin. The meteorological input data for the distributed model are collected at 7 met stations across the North Slope and distributed spatially using a kriging method. The finite element model coupled with the energy balance model calculates soil surface and sub-surface temperature and thaw depth. These programs were written to operate on a UNIX based workstation; however, the codes are being parallelized on the Cray T3D supercomputer. This model is based on the thermal energy balance method and considers slope, aspect, and surface conditions in addition to vegetation and soil moisture to calculate surface temperature. This thermal model when coupled to a hydrologic model can provide information valuable in the analysis of biological and physical processes, such as trace gas emissions and nutrient transport.