THERMAL RESPONSE OF THE ACTIVE LAYER TO CLIMATIC WARMING IN A PERMAFROST ENVIRONMENT

Global warming is occurring, the only question is what will be the magnitude of the temperature change and the temporal and spatial distribution? Existing models predict that the greatest change from present climatic conditions will happen in the polar regions. In the Arctic, continuous permafrost exists and climatic warming could have severe consequences. In this paper the consequences of global warming on the active layer are examined. Soil temperature data were collected over a four-year period at a field site near Toolik Lake, Alaska. A finite-element, two-dimensional, heat conduction model with phase change was used to predict soil temperatures at the site. After verification that the model could be used with confidence to predict the soil thermal regime, various climatic warming scenarios were used as inputs to estimate the thermal response for the next fifty years. The impact of climatic warming on the thickness of the active layer is reported.