Sensitivity of the lmd atmospheric circulation model to the albedo of snow-covered surfaces: preliminary results of feedbacks related to snow cover.

Summary In order to establish the role of feedbacks related to a decrease in snow cover in the context of global warming due to greenhouse gases, a new parameterization of albedo has been developed. This, using a global climate model, considers the most significant parameters of the observed large variability, such as vegetation, snow age, snow cover renewal rate and fraction of the surface covered by snow. Sensitivity studies to this parameterization are performed in seasonal and perpetual mode. We study aspects of the model's response concerning both surface albedo, ground temperature, snow fraction and some hydrological variables. For the validation of the results of the lmd model, a percentage snow cover climatology has been established using satellite data provided by noaa. The climatic impact of boreal deforestation was also analyzed over the northern hemisphere.