Spatial Variability of Snowmelt Rates at Scotty Creek, NWT

English Abstract:

At high latitudes, snow has a significant influence on hydrological and atmospheric processes. Portions of these regions are dominated by evergreen coniferous forests which affect energy and mass exchanges between the atmosphere and the land surface. Beneath a forest canopy, energy budget dynamics are strongly influenced by the large spatial variability of radiative and turbulent fluxes. The spatial variation of shortwave irradiance to snow is important to quantify as it can affect the depletion of snow covered area and areal melt rates. Currently, the magnitude of this variation has been sparsely quantified by field measurements during melt and hence, limits the physical basis with which spatial distributions of melt can be estimated. This study was conducted in the high-Boreal zone of discontinuous permafrost at Scotty Creek, NWT for the purpose of addressing these discrepancies. The specific objectives were to 1) compute the snowmelt energy balance in a high-latitude forested environment; and 2) determine the relative importance of the energy balance terms with respect to controlling the spatial distribution of melt energy and partitioning of radiative and turbulent fluxes. Point measurements of snowmelt were used in combination with aerial remote sensing, including high-resolution LiDAR, and the Cold Regions Hydrological Model to examine the spatial distribution of snowmelt rates. Preliminarily analysis suggests that under most circumstances, net radiation provides the majority of melt energy below the tree canopy.