Urban-rural contrasts in summer soil-surface temperature and active-layer thickness, Barrow, Alaska, USA

Increasing urbanization and development in the Arctic may exacerbate the local impacts of climate warming in areas underlain by permafrost. As part of the Barrow Urban Heat-Island Study (BUHIS), hourly air and near-surface soil temperatures (5 cm depth) were collected at 66 sites in and near Barrow, Alaska. Comparison of near-surface soil temperatures, categorized by land-cover type, revealed that urban temperatures in each category were higher than those in corresponding units of the surrounding undeveloped area. Mean summer soil-surface temperatures within comparable land-cover units were 0.3-2.3°C higher in the urban area. Active-layer thickness was greater by 15-40 cm at the urban sites than at locations with similar vegetation in the rural portions of the study area. Engineering criteria established from measurements made at 'rural' meteorological sites or from general maps of a large region may assume colder soils than are actually present, raising the possibility that inappropriate design criteria could be implemented. This risk will continue to grow as urbanization, resource development, and climatic changes increase.