Effective Scattering Albedo of Forests Retrieved by SMOS and a Three-Parameter Algorithm

Abstract

This letter illustrates results obtained using brightness temperature data collected by the Soil Moisture and Ocean Salinity radiometer and a three-parameter algorithm, retrieving soil moisture, vegetation optical depth, and the effective albedo of vegetation. Four eight-day time intervals have been considered. Only areas with a forest cover higher than 90% have been selected. For tropical forests, the retrieved albedo is in a range 0.05-0.07 and tends to decrease with an increasing optical depth. For these forests, the results are scarcely influenced by seasonal variations. For boreal forests of North America, the range of retrieved albedo is again 0.05-0.07 in July, but lower values are found in November for needleleaf forests of Canada and Northern U.S. For forests with higher optical depth, retrieved values of effective albedo show a lower spread.