Saturday, July 26, 2008

Life cycles of atmospheric aerosols can be illuminated with new technology

Science Daily: An aerosol mass spectrometer developed by chemists from Aerodyne Research Inc. and Boston College is giving scientists who study airborne particles the technology they need to examine the life cycles of atmospheric aerosols – such as soot – and their impact on issues ranging from climate change to public health.

BC Chemistry Professor Paul Davidovits and Aerodyne Principal Scientist Timothy B. Onasch say their novel spectrometer allows researchers to better understand what happens to these sub-microscopic particles that can absorb and scatter light and influence the lifetime of clouds.

"For scientists looking at climate change, the biggest uncertainty has to do with the effect of aerosol particles in the air," says Davidovits. "The issue is made that much more complex because aerosols can have different effects on climate. That means the target is constantly shifting."

The historic role of carbon-laden soot in climate change has been identified by researchers, particularly through ice samples taken from glaciers. Now scientists are focusing on tiny airborne particles of black carbon released into the atmosphere today in order to better understand the lifecycle of these aerosols in the atmosphere.

To that end, nearly 20 researchers from across the country brought other devices to the Davidovits lab this month to test and fine-tune these new tools developed by scientists from universities, industry and national laboratories at the forefront of this path-breaking science of the sky.

….Aerosols are somewhat fleeting. Unlike carbon dioxide, which can remain in the atmosphere for years, aerosols have an atmospheric life of about 10 to 20 days. In that time, they can absorb other molecules that alter their original state.

….Linked closely to the atmospheric effects of aerosols is a range of public health concerns, says Onasch. "There is a need on many fronts – from the climate to public health – for greater understanding of the role aerosol particles play in our lives and what's happening here is the scientific community rising to meet those needs," says Onasch.

This image, taken by Terra/MODIS instrument in December 2004 shows thick haze and smoke over the Ganges Basin in northern India. Major sources of aerosols in this area are believed to be smoke from biomass burning in the northwest part of India, and air pollution from large cities in northern India. NASA, Wikimedia Commons

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