Modeling evidence for recent warming of the Arctic soil thermal regime

Abstract

Daily soil temperature and thaw depth for the entire Arctic terrestrial drainage area are simulated using a one‐dimensional heat transfer model with phase change. Analyses of temperature trends at the soil surface and at 2 m depth are presented for the 23‐year time period 1980 through 2002. Soil warming is simulated for all permafrost regions, but is most pronounced (0.044°C/yr) at the surface in the continuous permafrost region. Trends for most recent years (1994–2002) are about three times higher. Active layer depth increases significantly for parts of Alaska and northern Canada, and southern and eastern Siberia. As assessed for the major river drainages, the most dramatic active layer deepening occurs in the Yenisey basin.