Autumn And Winter Smog (Particles)
During the cooler months (April to September), Melbourne is more affected by the accumulation of fine particles, which come from motor vehicle emissions, wood smoke, other combustion processes and photochemical processes in the air.
Temperature inversions in winter mean that warm air higher in the atmosphere traps pollutants in the layer of cold air closer to the ground. These inversions can last for several days and cause 'scummy' brown hazed horizons until dispersed by wind or rain.
The fine particles scatter sunlight, reduce visibility, soil buildings and fabrics and provoke existing respiratory diseases and other health problems.