mixing height

in atmospheric chemistry
https://doi.org/10.1351/goldbook.M03947
The height to which significant mixing of added pollutants occurs within the atmosphere. In reference to stack gases, it is considered the height at which stack @E01910@ begins mixing with the atmosphere as it leaves the stack.
Source:
PAC, 1990, 62, 2167. (Glossary of atmospheric chemistry terms (Recommendations 1990)) on page 2202 [Terms] [Paper]