The possibility of climatic warming in high-latitude zones has fueled growing concern about prospects for widespread melting of permafrost across large areas of the Arctic. The dynamics by which permafrost melts are not fully understood, however. Longstanding views that held conductive heat transfer as the primary mechanism have been challenged by new theories that hold that nonconductive heat transfer also plays an important role in the freezing and thawing of permafrost. This project will assess the degree to which each of these mechanisms and other possible processes affects permafrost dynamics in a variety of settings in central Alaska. Measurements of a variety of different soil, snow and ice, temperature, and moisture conditions will be collected at a set of paired permafrost and non-permafrost sites. These data will be used to analyze relationships among these different variables and to test different models of heat transfer within permafrost. This project will provide valuable new data on conditions within and immediately above the soil in permafrost and non-permafrost regions, and it will provide an effective test of competing hypotheses regarding heat transfer mechanisms that affect the stability of permafrost. In addition to contributing to new insights about permafrost dynamics, this project also will make methodological contributions by testing the efficacy of new instruments in harsh environments.
