Spatial distributions of snow cover properties in the boreal forest depend on depositional and post-depositional factors including the spatial variation of snowfall, interception/sublimation losses from the canopy and exposure to wind and components of the surface energy exchange. We use data collected during the winter and thaw periods in 1994 and 1995 from test areas of the Boreal Ecosystem Atmosphere Study (BOREAS) to illustrate the effects of forest canopy properties on spatial and temporal trends of snow on the ground. Within conifer and mature deciduous forest stands, with tree heights and/or canopy cover greater than some threshold, we found no significant statistical difference in snow water equivalence of snow between crowns. Snow depths tended to be greater in the taller or more dense stands where lower net energy fluxes resulted in snow with lower density. The main contrast in snow properties resulted from relative exposure to wind. Large open areas had less snow water equivalence and higher average densities. We explored the potential of using standard forest inventory products, in the form of digital maps of forest attributes, to use the empirical relationships of snow and land cover to construct maps of snow properties across BOREAS test areas in Saskachewan and Manitoba, Canada. The map products had to be supplemented with remote sensing data to fill in tree stand properties in unproductive areas, such as treed muskeg. We show how maps of snow water equivalent show the potential for determining total water volume over large areas.

#Atmospheric Environment Service
Climate Research Branch
4905 Dufferin Street, Downsview, Ontario M3H 5T4 CAN
E-mail: john.metcalfe@ec.gc.ca anne.walker@ec.gc.ca