SPACEBORNE REMOTE-SENSING FOR SNOW HYDROLOGY APPLICATIONS

Certain satellite-based remote sensing for snow hydrology applications has been very positive, namely, snow areal extent mapping using visib le and near-infrared sensors and snow water equivalent using passive m icrowave techniques. Although certain problems are yet to be solved, v ery specific applications have become operational. Data from the NOAA- AVHRR sensor are used to produce snow extent maps for about 4000 basin s in North America and the data are distributed electronically by the NWS National Operational Hydrologic Remote Sensing Center. At the Cana dian Climate Centre, a method has been developed for real time estimat ion of areal snow water equivalent over the Canadian prairies using mi crowave brightness temperatures, and the snow water equivalent maps ar e distributed to operational hydrological forecasters. Current researc h may also prove fruitful for estimates of snow wetness or active melt ing, snow albedo and snow grain size. It appears that forthcoming impr ovements in passive microwave spatial resolution should increase the a pplicability of the data for snow hydrology. The spectral and spatial resolution of the visible/near-infrared data will also be improved wit h the launch of EOS/MODIS. Combinations of sensors and integration wit h other types of data will further improve the suitability of spacebor ne data.