EXAMPLES

LOOPING—large-scale turbulent eddies cause sizable parcels of air, together with portions of the plume, to deviate from a straight downwind direction
(figure available in print form)B. CONING—the shape of the plume is commonly vertically symmetrical about what is call the plume line.
C. FANNING—suppressed vertical mixing, but not horizonal mixing entirely causes the plume to spread only parallel to the ground and appears to take on the shape of a fan as seen from below.
D. LOFTING—the lapse rate in the upper portion of the plume is unstable and in the lower it is stable. Mixing is vigorous in the upward direction.
E. FUMIGATION—poses a potentially serious air pollution situation. Here the plume is released just under an elevated inversion layer. When the low-level unstable lapse rate reaches the plume, the effluent suddenly mixes downward toward the ground.

In the effluent from a smelter in a valley is trapped in a radiational inversion, diffusing neither upward or downward, but drifting down the valley, the ground level concentration will be highest. The daily uniform warming of the valley floor erodes the inversion from beneath, and when the layer containing pollutants becomes unstable widespread fumigation occurs along a great length of the valley. SEE DIAGRAM BELOW.