Aggregated and distributed modelling of snow cover for a high-latitude basin

A distributed land-surface model is used to simulate the seasonal cycle of snow cover for a high-latitude basin. In comparison with the distributed model, a simulation using surface parameters and meteorological data averaged over the entire basin overestimates the peak snow accumulation and underestimates the duration of snow cover. Dividing the basin into a small number of elevation bands and performing separate simulations for each band greatly improves the results. The improvement is less marked if information on the elevation dependence of vegetation cover and meteorological conditions is not used. Distributed simulations with different models produce a wider range of results than distributed and aggregated simulations with the same model.