Mapping of Surface Albedo over Mackenzie River Basin from Satellite Observations

This chapter presents the approach and results of mapping surface albedo and bi-directional reflectance distribution function (BRDF) properties over the Mackenzie River Basin (MRB). Satellite observations from three types of sensors were used: (1) the Advanced Very High Resolution Radiometer (AVHRR) sensor onboard the NOAA platforms, (2) the VEGETATION (VGT) sensor onboard the SPOT platforms, and (3) the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor onboard the TERRA platform. The data collected using these sensors span the period of 1985 to 2004. Seasonal and interannual variability of spectral and broadband albedo over the MRB was analyzed. Broadband albedo averaged over the region changed from 0.11±0.03 in summer to 0.4-0.55 in winter. No substantial long-term systematic trends in surface albedo could be detected over the study period, mainly due to large interannual variability, uncertainties in sensors properties, atmospheric correction, and retrieval procedure.