A global albedo data set derived from AVHRR data for use in climate simulations

We present a global 1-km albedo dataset derived from Advanced Very High Res olution Radiometer (AVHRR) satellite remote sensing data, a global land cov er classification and field observations of typical land surface bidirectio nal reflectance distribution functions (BRDFs). There is a clear need for s uch a global albedo map for use in atmospheric radiative transfer models. A land cover classification based on surface structure is employed and class correspondences used to generate a structural class map from an existing e cological global land classification. Representative field measurements of BRDF are assigned to each of the structural classes allowing us to retrieve BRDF shape parameters and albedo for each class using a semiempirical mode l. These parameters were adjusted using global AVHRR data to account fur in tra-class variations of surface reflectance. Albedos were calculated from t he adjusted parameters and summarised by land cover type, continent and sea son.