Process by which up to 25% of radiant energy from the sun is reflected or scattered away from the surface by clouds. Serves the greatest importance in the Atmospheric Heat Budget. Large errors in the assumed value of this variable may have important effects on computer models of the atmosphere. [Radiation and the Cloud Process in the Atmosphere; Liou, K.N.; 194; 1992; Oxford Press; Oxford.] [ Man's Impact on the Climate; Mitchell, Murry; Ed. Williams A. Matthews; 173; 1971; Colonial Press; Baltimore.] [Atmospheric Environment; v36; 5479-5489; 2002.] [Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere; v26; 239-245; 2001.]