A distribution function

,
in which the logarithm of a quantity is normally
distributed, i.e.

where

is a Gaussian distribution. The size distributions of atmospheric aerosols are often
described using this distribution function, although the term also applies to gaseous
pollutants.
Source:
PAC, 1990, 62, 2167
(Glossary of atmospheric chemistry terms (Recommendations 1990))
on page 2199