The decay of organic aerosols

摘要

The chemistry of organic aerosols has been somewhat neglected on the assumption that they are eliminated from the atmosphere mainly by rainfall. Laboratory studies indicate that a rethink is called for. Fine particles and droplets suspended in the atmosphere have a key role in environmental issues such as climate and human health. Over the oceans, such aerosols consist mainly of sulphates, but above continents they are mostly organic matter. Organic aerosols come from many sources, including smoke particles from burning fuels and biomass, and the light-induced oxidation of volatile hydrocarbons, both natural and man-made. The main process that removes organic aerosols from the atmosphere has been assumed to be precipitation, but writing in Geophysical Research Letters Molina and colleagues suggest that another elimination route could be just as important.