A Note on the Albedo of Surfaces

Abstract

The albedo of a variety of surfaces was measured for a total of approximately 400 hr with Middleton solari-albedometers whose outputs were recorded by a computer-controlled data acquisition system. The albedo for each surface was expressed as a function of solar zenith angle, with strong relationships between the two being obtained for most surfaces. The dependence became stronger, i.e., the correlation coefficient between the two sets of data rose, as the transmissivity increased. All surfaces showed two characteristic albedo zenith angle curves corresponding to AM and PM observations, the PM curves generally being displaced farther from the origin. The feature is explained in terms of the compound effect of solar elevation and haziness. Irrigation increased the albedo during AM periods but showed no significant effect on PM values.