Abstract
Aerosols are particles - solids or liquids - suspended in the atmosphere. Natural aerosols include dust from desert areas, salt from ocean spray, volcanic ash and semi-burnt particles from fires. Human activities generate other types of particles in addition to natural aerosols. They are transported by the atmosphere over great distances and settle far from their origin. Aerosols have a climatic impact that runs counter to that of greenhouse gases. They can be observed by satellite or from the ground using dedicated programs.
