Atmospheric Dispersion Index
Atmospheric dispersion is
the process by which the atmosphere mixes
and transports particulates, such as smoke,
away from their source. The Atmospheric
Dispersion Index (ADI) was developed by the
U.S. Forest Service to assess the impact of
prescribed burning activity on atmospheric
smoke concentrations and air quality. The
same processes responsible for good smoke
dispersion also contribute to erratic fire
behavior and may present very hazardous
conditions.
Interpretation of Daytime ADI Values
ADI |
DESCRIPTION |
| 0-20 |
Poor
dispersion, stagnant if persistent. |
| 21-40 |
Poor
to fair, stagnation may be indicated
if accompanied by low wind speeds. |
| 41-60 |
Generally
Good |
| 61-80 |
Very
good dispersion. 75 and above, Control problems
likely. |
| 80
+ |
Excellent
dispersion, Control problems
expected. |
Interpretation of Nighttime ADI Values
ADI |
DESCRIPTION |
| 0-2 |
Poor |
| 3-4 |
Poor
to Fair |
| 5-8 |
Good |
| 8
+ |
Very
Good |
|