Micrometeorological measurements and instrumentation to support remote sensing observations of an alpine snowcover

Remote sensing measurements from satellites and aircraft provide radiometric information that can be used to calculate spatial distribution of snow properties over large areas. This information can then be combined with physical models of snowpack thermodynamics to estimate distribution of melt rates over a region or basin. However, this application of remote sensing has been severely limited because data from which to determine relationships between the physical and radiometric properties of snow have not been available. To calibrate remote sensing data we must first determine the energy and mass balance of the snow at an experimental site, measure those properties that affect snow's radiometric properties, and compare these to reflection and emission data. To satisfy these needs we have maintained a snow research and experiment site at Mammoth Mountain, California. We describe instrumentation and techniques to continuously monitor the energy and mass balance, and to measure critical snow properties, such as liquid water content, temperature and density profiles, crystal shape, and effective grain size under a variety of conditions during the snow season.