AbstractThe Mackenzie GEWEX Study (MAGS) is a Canadian investigation that has the objective of understanding and modelling the water and energy cycles and their roles in the climate system in the high-latitude Mackenzie River basin, including assessing potential changes due to climate variability and change. The Climate Research Branch (CRB) of the MeteorologicalService of Canada has investigated snow-cover variations over the MAGS region using snow water equivalent (SWE) datasets derived from Special Sensor Microwave/Imager (SSM/I) passive-microwave satellite data for the winter seasons 1988–98. The SWE datasets were derived using four CRB algorithms for prairie, coniferous-forest, deciduous-forest and sparse-forest land-cover types and then evaluated against available in situ SWE measurements for MAGS subbasins. Overall, the SWE algorithms produce reliable estimates (within 10–20mm of in situ SWE measurements) for the validated part of the MAGS region, although some areas exhibit underestimations of > 30 mm, which may be due to the presence of a high density of lakes or a decreased microwave sensitivity to high-SWE conditions (>100mm). A time-series dataset of SSM/I-derived SWE for1 March of each year from 1988 to 1998 has been produced as a MAGS deliverable, which provides important information on the spatial and temporal variability in snow cover over the Mackenzie River basin. This dataset has been used in the assessment of snow-cover outputs from MAGS hydrological and climate-modelling investigations.
Snow-cover variations over the Mackenzie River basin, Canada, derived from SSM/I passive-microwave satellite data
