Evaluation of new snow depth and mass data sets for North America

Two new gridded daily snow depth data sets for North America are discussed and compared to other sources of snow cover information. The 1° latitude by 1° longitude gridded snow depth data set for the period of 1960-2003 is unique in the extensive quality control procedures applied to all available surface observations. The new gridded snow depth data are examined for long-term changes in snow cover extent and depth on fixed days throughout the winter season. Snow cover extent based on visible satellite data is compared to the new snow depth data set for the period 1966-2000. Additionally, satellite microwave snow extent and depth from 1978-2000 is compared to the new data set. The snow depth is also used with modeled snow densities to develop a gridded snow mass data set for the continent. Various applications of the new data set in the fields of climate change and hydrology are discussed.