Thursday, 19 June 2014

Albedo

The amount of sun's rays that is reflected by an earthly body is called albedo. The word albedo is derived from albus, a Latin word for white.

Albedo is a measure of how much light that hits a surface is reflected without being absorbed.  Something that appears white reflects most of the light that hits it and has a high albedo, while something that looks dark absorbs most of the light that hits it, indicating a low albedo.


It is the reflection of a certain area of earth, like snow and mountains, on the surface. 
For example, the albedo of snow covered mountains hurts the eyes. 

Material
Albedo values (% reflected)
Fresh snow
            80% - 95%
Light roof
            35% - 50%
Grass
            25% - 30%
Bricks and stone
            20% - 40%
Concrete dry
            17% – 27%
Water bodies
            10% - 60%
Forest
            10% - 20%
Crops and grassland
            10% - 25%
Dark roof
            8% - 18%
Asphalt
            5% - 10%
Earth’s albedo (average)
            31%