The albedo of a tropical evergreen forest

The diurnal variation of the average albedo, during 1970, over a tropical dry evergreen forest and a nearby clearing was investigated. The study is based on a most comprehensive set of solar radiation data in Southeast Asia. A strong dependence of the albedo on the zenith angle is evident. This dependence is subdued during cloudy days. The average midday albedo for the winter monsoon season is 10.6 for the forest and 13.4 for the clearing; for the summer monsoon it is 12.0 for the forest and 14.6 for the clearing. Generally, results show great uniformity. The largest standard deviations are 0.05 with a more representative value in the range 0.01–0.02.