Analysis of Year-to-Year and Seasonal Variability of Land Surface Albedo in the Russian Actinometric Network

Data registered in the Russian actinometric network are used in analyzing time series of hourly albedo values for the period 1976-1995. The mean monthly midday albedos reveal a considerable year-to-year variability averaging 5-8%. The maximum variabilities are greater by a factor of two to three. Despite a definite diversity in behavior of albedo, most observation points exhibit stable trends in their long-term changes. During the cold season there is an albedo decrease, whereas in the warm season there is an albedo increase. The linear trends are about 0.5-1.0% per year. At individual stations during individual months during the cold season of the year there is a trend toward an albedo increase. Changes in the annual albedo variability are related to alternation of cold and warm winters.