Assimilation of MODIS snow cover and real time snow depth point data in a snow dynamic model

This paper describes a data assimilation method that uses observations of snow covered area and snow gauges measurements to update a simple hydrological model. The assimilation method uses snow gauges and snow cover area information as part of a nudging scheme to modify the modeled distribution of snow and the snow water equivalent state. This method permits an optimal combination of model simulations and observations, as well as propagation of information across model states and it is applied in a mountainous area of the Alps (Valle d´Aosta).