The ratio of the amount of
electromagnetic radiation reflected
by a body to the amount incident upon it, often expressed as a percentage,
as, the albedo of the earth is 34% . Compare
The concept defined above is identical with reflectance. However, albedo is more commonly used in astronomy and meteorology and reflectance in physics.
Albedo is sometimes used to mean the flux of the reflected radiation as, the earth albedo is 0.64 calorie per square centimeter. This usage should be discouraged.
The albedo is to be distinguished from the
spectral reflectance which
refers to one specific wavelength (monochromatic radiation).
Usage varies somewhat with regard to the exact wavelength interval implied in albedo figures; sometimes just the visible portion of the spectrum is considered, sometimes the totality of wavelengths in the solar spectrum.
This article is based on NASA's Dictionary of Technical Terms for Aerospace Use