Distribution
Anthropogenic aerosol: climatic and environmental impact

Given the distribution of aerosol sources and its lifetime in the atmosphere, its spatial and temporal distribution is highly heterogeneous. Its effect on the equilibrium of the coupled Earth/atmosphere system is therefore preferentially regional. A rough average of the environmental impacts of aerosol, such as radiative impacts, is certainly an indicator, but can only be a small part of a wider reality.

The global distribution of aerosol is well illustrated in figure 4 . This is a map of average optical thickness at a wavelength of 550 nm for the month of August 2003. It has been deduced from satellite observations by the Modis (moderate resolution imaging spectroradiometer) instrument on board a polar-orbiting...