ALBEDO

The reflectivity of a surface, often expressed as a percentage of the solar radiation that falls on the Earth’s surface. The average global albedo is about 34% (i.e. that percentage of the total solar radiation reaching the Earth’s surface is reflected back into the atmosphere). However, albedo values vary greatly from place to place depending on the precise nature of the surface (ice, snow, different types of vegetation, etc.). The albedo for fresh clean snow exceeds 80%, but is much reduced for coarsely crystalline glacier ice (50%). For grassland, the albedo ranges between 30% and 20%, and for a dark peaty soil it is less than 10%. Water generally has a low albedo (between 5% and 10%) unless the Sun is at a low angle, when the albedo can be in excess of 50%.