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Updated: Jul 2, 2026

Production and Measurement of Organic Particulate Matter in the Harvard Environmental Chamber
Published on: November 18, 2018
Light intensity and light source influence on secondary organic aerosol formation for the m-xylene/NO(x)
Bethany Warren1, Chen Song, David R Cocker
1Department of Chemical and Environmental Engineering, Bourns College of Engineering, Center for Environmental Research and Technology (CE-CERT), University of California, Riverside, California 92521, USA.
Abstract:
A series of m-xylene/NO(x) photooxidation experiments were conducted to determine the influence of light intensity and radiation spectrum on secondary organic aerosol (SOA) formation within the UC Riverside/CE-CERT environmental chamber. The environmental chamber is equipped with 80 115-W black lights and a variable voltage 200 kW argon arc lamp that emits a wavelength spectrum more similar to natural light. SOA formation increased significantly with light intensity, measured as the photolysis rate of NO2 to NO (k1), increased from 0.09 to 0.26 min(-1). The argon arc lamp produced approximately 20% more SOA than black lights at a k1 of 0.09 min(-1) for similar amounts of m-xylene consumed. These results may help explain the variation of SOA formation between environmental chambers and the differences between measured SOA in the ambient atmosphere versus environmental chamber predictions.
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