Albedo is defined as high solar reflectance
i.e. the earth's capability of bouncing the sun's rays back into the stratosphere. If a surface absorbs all light it looks black and has an albedo of 0; if it is perfectly reflective it looks white and has an albedo of 1.
All surfaces, in fact all objects, have an albedo within those two numbers. A new sheet of copy paper has an albedo of 1 while a brick wall or a freshly plowed field has an albedo closer to 0 than to 1.
When the rays are absorbed or bounced, so is the accompanying heat from those rays. Thus the many chocolate colored roofs and black parking lots in populated areas create an urban heat island effect which may make a city 3° to 8° warmer then less populated nearby areas. This also impacts air quality as hotter air is dirtier air.
|
