Influence of Climate and Environmental Factors on the Thermal and Moisture Regimes of the Layer and Permafrost

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Recent unexpected and unexplained discoveries of a large amplitude temperature cycle in the active layer and permafrost from Prudhoe Bay to the Brooks Range, Alaska have been identified. Observations include large and systematic changes in the active layer, a large amount of unfrozen water in the frozen active layer, near-surface permafrost at some sites, and large spatial gradients in the active layer and permafrost surface temperatures. These changes indicate that the current understanding of climate-active layer interactions are not well understood. Warmer temperatures from increased greenhouse gases have been predicted in the Arctic. These temperature changes could cause permafrost to thaw as the active layer becomes thicker. A better understanding of the relationships among the atmosphere, soil surface active layer, and permafrost is required to interpret the rate and extent of permafrost degradation, modifications to its regime, release of carbon and trace gases by thawing permafrost, changes in soil moisture, and the hydrological cycle. This proposed research contains field and laboratory measurements, and analyses and interpretations of the data which will be obtained from six long-term study sites along a transect from Prudhoe Bay across the coastal plain and to the foothills of the Brooks Range. These sites are in undisturbed areas and span a wide range of permafrost, climatic, and environmental conditions. They have a relatively long term data base (since 1983). This research will investigate how the active layer and continuous permafrost, in a variety of climatic and environmental regimes, has responded and continues to respond to climatic change.