Surface Energy Balance of the Western and Central Canadian Subarctic: Variations in the Energy Balance among Five Major Terrain Types

Abstract

In this study, the surface energy balance of 10 sites in the western and central Canadian subarctic is examined. Each research site is classified into one of five terrain types (lake, wetland, shrub tundra, upland tundra, and coniferous forest) using dominant vegetation type as an indicator of surface cover. Variations in the mean summertime values (15 June–25 August) of the energy balance partitioning, Bowen ratio (β), Priestley–Taylor alpha (α), and surface saturation deficit (D_o) are compared within and among terrain types. A clear correspondence between the energy balance characteristics and terrain type is found. In addition, an evaporative continuum from relatively wet to relatively dry is observed among terrain types. The shallow lake and wetland sites are relatively wet with high Q_E/Q* (latent heat flux/net radiation), high α, low β, and low D_o values. In contrast, the upland tundra and forest sites are relatively dry with low Q_E/Q*, low α, high β, and high D_o values.