Volume extinction coefficient

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volume extinction coefficient

A measure of the depletion of monochromatic radiance passing through some medium in a constant direction.

The volume extinction coefficient equals the fractional depletion due to absorption and scattering when monochromatic radiance passes unit distance through a medium in a constant direction. Units are inverse length or km-1. Values depend critically on the medium being traversed, as well as the wavelength. For example, in a Rayleigh atmosphere the volume extinction coefficient at a wavelength of 0.5 μm is less than 0.02 km-1, whereas in a wet cloud it may exceed 100 km-1 at the same wavelength.

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