Comparison of MODIS and SnowStar Snow Maps in Scandinavia

In this study, we look at the melt season in the spring of 2004 in the southern part of the Fenoscandia region, which includes Finland, Sweden and Norway, to determine the relative accuracy of the Moderate-Resolution Imaging Spectroradiometer (MODIS) snow maps as compared to the maps which employ a modified SnowStar algorithm. SnowStar is an operational snow-mapping system developed in Norway for mapping snow in Scandinavia. The SnowStar maps use 250-m MODIS data as input and a cloud mask which is tuned to the Fenoscandia region. Snow maps from MODIS produce global, daily maps using an automated algorithm which is not tuned to any particular land cover or set of cloud conditions. For the four dates studied, the preliminary assessment is that the regionally-tuned cloud mask of the SnowStar maps accounts for most of the difference in amount of snow mapped between map products.