Determination of the Shortwave Anisotropic Function for Clear-Sky Desert Scenes from ScaRaB Data: Comparison with Models Issued from Other Satellite Data

Abstract

Abstract Determination of directional albedo and bidirectional anisotropic function are necessary to the radiance-to-flux conversion. The most recent model, used for the Earth Radiation Budget Experiment data, is based on data from the sun-synchronous Nimbus-7 mission that is observed close to local noon. Because the desert zones are restricted in latitude (20°–35° in each hemisphere), only a small range of solar zenith angles was sampled. Here, the author considers for clear-sky desert regions the improvements that can be made using non-sun-synchronous satellite data, precessing in local time. This study made from ScaRaB data (Scanner for Radiation Budget, on board the Meteor-3-07 satellite) concerns the clear-sky deserts. The four great deserts on the earth (the Sahara, Arabian Desert, Namib-Kalahari, and Australian Desert) have been considered with 1.25° latitude × 1.25° longitude study areas. A normalization method, explained here, makes it possible to combine the values of bidirectionel anisotropic r...