A Study of Land Surface Albedo Conversion Formulas Using Three-Dimensional Canopy Radiative Transfer Modeling

Land surface albedo defines the ratio of shortwave radiation absorbed by the surface and controls the surface energy balance, thus is important for environmental and climate scientific communities. Remote sensing is the only means to globally map land surface albedo, however for it to be of use to the aforementioned communities, it must be accurate with respect to Global Climate Observing System (GCOS) requirements. Sources of error are introduced in each step of the provision of land surface albedo products, whereby this study intends to investigate sources of error introduced by the narrowband-to-broadband conversion formulae step. Radiative transfer modeling of vegetation is used to simulate spectral albedo over complex 3D vegetation canopies, then broadband-to-narrow conversion formulae for numerous sensors applied on the spectral albedo to compute broadband albedo, and the accuracy of formulae investigated. Results indicate that the effectiveness of conversion formulae is determined by the sensor, depending on the placement and number of the sensor wavebands, ecosystem complexity and the broadband range of the broadband albedo.JRC.D.6-Knowledge for Sustainable Development and Food Securit