Within-slope variability of ground heat flux, subarctic Yukon

This study examined local variability of heat flux within a north-facing hillslope in Wolf Creek basin, Yukon, during the thawed season of 1997. Ground heat flux was calculated by: (1) assessing vertical conduction and convection inputs (Q(Gv)) using nearsurface temperature gradients and rainfall and (2) combining the sensible heat from ground temperature change with the latent heat associated with melting ground ice (Qc,) Seasonally, the coefficient of variation (cv) of Q(Gv) was 20%, with most of the variation accounted for by changes in wetness and soil properties. Vertical convection of heat by infiltrating rainfall accounted for less than 3% of Q(Gv). Measurements of Q(Gs), which incorporate lateral heat transfer associated with groundwater Glow, has a cv of 40%. Footslope sites do not have permafrost because of downslope advection of heat from groundwater and Q(Gs) was 2 to 3 times greater than upslope permafrost sites. Q(Gv) and Q(Gs) were similar at the upslope locations, however, the active layer depth varies depending on the ice content of the frozen soil.