Angstrom exponent
The Angstrom exponent or Ångström exponent is a parameter that describes how the optical thickness of an aerosol typically depends on the wavelength of the light. == Definition == In 1929, the Swedish physicist Anders K. Ångström found that the optical thickness of an aerosol depends on the wavelength of light according to the power law τ λ τ λ 0 = ( λ λ 0 ) − α {\displaystyle {\frac {\tau _{\lambda }}{\tau _{\lambda _{0}}}}=\left({\frac {\lambda }{\lambda _{0}}}\right)^{-\alpha }} where τ λ {\displaystyle \tau _{\lambda }} is the optical thickness at wavelength λ {\displaystyle \lambda } , and τ λ 0 {\displaystyle \tau _{\lambda _{0}}} is the optical thickness at the reference wavelength λ 0 {\displaystyle \lambda _{0}} .