Diffraction pattern

From Glossary of Meteorology

diffraction pattern

An interference pattern of scattered light centered on a scattering angle of 0°.

This pattern is due to the various phase relationships among the different paths that the electromagnetic radiation takes in going around, or through, a scattering particle, leading to constructive or destructive interference. In general, the larger the cross section of the particle, or the shorter the wavelength of the radiation, the narrower the angular spread of the diffraction pattern.