The subdiscipline of meteorology devoted to the study of air pollution. Topics include sources of pollutants, emission rates, plume rise, fallout, dry and wet deposition, chemistry, precipitation scavenging, dispersion (molecular diffusion and turbulent transport), short- and long-range transport (advection), trapping, venting by cumulus clouds, complex terrain and mesoscale circulations, receptors, impact on society, alerts and episodes, policy and regulation, modeling, prediction, control, and climate change.