The atmosphere acts as a dispersing agent for air pollutants. Dispersion causes beneficial pollutant reduction near the source and harmful pollutant increases at the receptors.
Dispersion takes place through horizontal transport and vertical mixing in the lower atmosphere.
Horizontal transport depends on location as well as on elevation above ground, and to some extent on time of day. The summertime dispersion in the Southeast is typically poor due to stagnating air masses. On the other hand, the western and northern sections of OTAG are typically well ventilated. As a consequence the horizontal dispersion of elevated sources exceeds the dispersion from low level sources. Transport wind vector during low ozone days.