Single-scattering albedo is the ratio of scattering efficiency to total extinction efficiency (which is also termed "attenuance", a sum of scattering and absorption). Most often it is defined for small-particle scattering of
electromagnetic waves
In physics, electromagnetic radiation (EMR) consists of waves of the electromagnetic (EM) field, which propagate through space and carry momentum and electromagnetic radiant energy. It includes radio waves, microwaves, infrared, (visible) lig ...
. Single-scattering albedo is unitless, and a value of unity implies that all particle extinction is due to scattering; conversely, a single-scattering albedo of zero implies that all extinction is due to absorption.
For spherical particles one can calculate single-scattering albedo from
Mie theory
The Mie solution to Maxwell's equations (also known as the Lorenz–Mie solution, the Lorenz–Mie–Debye solution or Mie scattering) describes the scattering of an electromagnetic plane wave by a homogeneous sphere. The solution takes the f ...
and knowledge of bulk properties of material such as
refractive index
In optics, the refractive index (or refraction index) of an optical medium is a dimensionless number that gives the indication of the light bending ability of that medium.
The refractive index determines how much the path of light is bent, or ...
. For non-spherical particles one could use
discrete dipole approximation or other methods of
computational electromagnetics
Computational electromagnetics (CEM), computational electrodynamics or electromagnetic modeling is the process of modeling the interaction of electromagnetic fields with physical objects and the environment.
It typically involves using computer ...
. The albedo of particles of shapes which are easily parameterized in non-standard co-ordinate systems may be determined through solutions of Maxwell's equation analogues in such coordinate systems. Scattering albedo equations have yet to be determined in elliptical, toroidal, conical and many others. Derivation and solutions to such equations is a field of ongoing research.
See also
*
Light scattering by particles
Light scattering by particles is the process by which small particles (e.g. ice crystals, dust, atmospheric particulates, cosmic dust, and blood cells) light scattering, scatter light causing optical phenomena such as the Rayleigh scattering, blue ...
*
Albedo
Albedo (; ) is the measure of the diffuse reflection of sunlight, solar radiation out of the total solar radiation and measured on a scale from 0, corresponding to a black body that absorbs all incident radiation, to 1, corresponding to a body ...
References
*H. C. van de Hulst: ''Light scattering by small particles'', New York, Dover, 1981.
*C. F. Bohren, D. R. Huffmann: ''Absorption and scattering of light by small particles''. New York, Wiley-Interscience, 1983.
Scattering, absorption and radiative transfer (optics)
Atmospheric radiation
Aerosol measurement
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