To find some order in this chaos, Jimenez and his colleagues began looking at organic particles with a more holistic mindset. Through a series of field observations and lab experiments conducted all over the world, they found that organic matter ultimately tends to evolve toward a similar end, regardless of the source or where the matter occurs in the atmosphere
"What surprised us is how similar the organic matter looked as we went from the heart of Mexico City to an island in Japan to a forest in Finland or a mountain in the Swiss Alps," said Jimenez.
"The atmosphere acts like Dan Aykroyd's Bass-O-Matic, making similar-looking goop almost no matter what you start with," said Neil Donahue, a study co-author with Carnegie Mellon University.
The study found that this particle soup can be boiled down into a few measurable characteristics, such as the oxygen-to-carbon ratio, which are key variables for predicting climate and air quality.
"Using a novel aerosol mass spectrometer, we found that the atmosphere blurs the differences between aerosols emitted by different sources relatively quickly," said Manjula Canagaratna, a co-author from Aerodyne Research in Boston. "This is potentially a very important simplification, which is key to improving air quality and climate models."
Of importance in the study was the creation of a chemical "map" by Donahue. The map provides some of the first clear visualization of how these organic aerosols change once they become a part of the particle soup.
The map tracks two key properties -- volatility, or the tendency to evaporate, and the oxygen-to-carbon ratio -- that evolve as organics make their way through the atmosphere. This ratio is important because it is an i
|Contact: Jose-Luis Jimenez|
University of Colorado at Boulder