Aerosols (particles suspended in the atmosphere) are responsible for scattering and absorbing sunlight. This is most beautifully seen in the bright red sunsets observed when there is a lot of aerosol, but is also known by the haze that restricts visibility in cities.
The Centre is involved in the measurements of optical impact of aerosols, both through the program at Cape Grim (in very close collaboration with the Global Atmosphere Watch group at the Bureau of Meteorology) and through the study of bushfires.