Investigation on the relation between physical and radiometrical properties of snow covers

The extension of the snow cover and the distribution of different snow types can be considered an indicator of global changes and a key parameter in the global radiation balance of the Earth. More-over, in the mountain regions the possibility to monitor the snow characteristics using remote sens-ing images can support hydrological studies. The reflectance of snow is determined in part by the size and shape of snow crystals, especially in the short wave infrared (SWIR) wavelength region; for this reasons it is possible to use remote sensed images to map differences in the snow cover. The Specific Surface Area (SSA) of snow is a crucial variable for understanding snow chemistry and air snow exchanges of chemical species that can also be related to snow reflectance. This study shows how field spectral measurement and SSA data of snow samples can be used as input data for classifying Landsat TM SWIR images in order to obtain maps of different snow types. This method can be a very useful tool to monitor the snow metamorphism, air-snow exchanges and cli-mate.