turbidity, \(\tau\)

in light scattering
https://doi.org/10.1351/goldbook.T06533
The apparent @A00028@ of the incident radiation due to @S05487@. For small particles, direct proportionality exists between turbidity and the @R05159@.
Source:
Purple Book, 1st ed., p. 66 [Terms] [Book]
See also:
PAC, 1990, 62, 2167. (Glossary of atmospheric chemistry terms (Recommendations 1990)) on page 2218 [Terms] [Paper]