Rayleigh scattering

https://doi.org/10.1351/goldbook.R05160
The
scattering
of light by particles and molecules which are much smaller than the
wavelength
of the light. In the ideal case, the process is one of pure dipole and induced dipole interactions with the electric field of the light wave. The
scattering
cross section for light of
wavelength
λ is proportional to λ4.
Source:
PAC, 1990, 62, 2167. (Glossary of atmospheric chemistry terms (Recommendations 1990)) on page 2209 [Terms] [Paper]