Changing Extent of Lakes and Permafrost on the North Slope of Alaska

Permafrost has been monitored in a trans-Alaska transect from Valdez (61.13 N) to West Dock at Prudhoe Bay (70.26 N) since completion of the Alaskan pipeline in 1977. These measurements reveal a consistent pattern of recent warming. The largest change is seen on the North Slope where permafrost has warmed by 3-4 degrees Celsius since 1988. To examine the wider implications of the changing properties of permafrost in the North Slope we use two approaches. A numerical model of permafrost is set up and applied to the Kuparuk River drainage basin in order to quantify the spatial and temporal variability of surface energy fluxes, while changes in the land surface since the mid-1980s is examined by satellite remote sensing. The model shows sensitivity of thaw depth to hydrological processes in the active layer. The remote sensing analysis revealed substantial changes in the extent and number of thermokarst lakes.