A simple method is developed to obtain the relative atmospheric aerosol content over low-albedo surfaces (water) from observations of the Erts (now Landsat) type. The method is based upon a derived relationship between the aerosol optical thickness and the satellite-observed upward scattered solar radiation and upon the proportionality of aerosol optical thickness to aerosol column density. The method is successfully applied to Erts 1 observations of the Middle East by comparing the aerosol content on a day when the meteorological observations indicated high atmospheric dust content with that on a day on which normal meteorological conditions prevailed.