Organic aerosol mystery solved

Scientists believe they may have cracked an important conundrum in atmospheric chemistry: how a volatile molecule released by plants helps to form aerosols that can have a profound effect on weather and climate systems.

Isoprene, C₅H₈, is emitted by deciduous plants and is the largest source of hydrocarbons other than methane to enter the atmosphere - estimated at more than 500 million tonnes each year. It has been known for many years that isoprene participates in the formation of aerosols - tiny liquid droplets suspended in the atmosphere. These 'secondary organic aerosols' play an important part in the formation of clouds and the cycling of water in the atmosphere. However, their composition and the chemistry of their formation has remained elusive, leaving a large gap in knowledge for those trying to develop comprehensive atmospheric models. Isoprene itself is too volatile to attach to particles in the atmosphere and create aerosols.  More...

http://www.rsc.org/chemistryworld/News/2009/August/06080902.asp