Nitrogen dioxide and the hydroxyl radical combine in the atmosphere to make either nitric acid or peroxynitrous acid; the so-called branching ratio of these two chemicals is important in models of ozone production.
Team says current models may underestimate ozone levels; findings made by characterizing rates of key chemical reactions. PASADENA, Calif.—A team of scientists led by researchers from the California Institute of Technology (Caltech) and NASA's Jet Propulsion Laboratory (JPL) have fully characterized a key chemical reaction that affects the formation of pollutants in smoggy air. The findings suggest that in the most polluted parts of Los Angeles—and on the most polluted days in those areas—current models are underestimating ozone levels, by between 5 to 10 percent. The results—published in this week's issue of the journal Science —are likely to have "a small but significant impact on the predictions of computer models used to assess air quality, regulate emissions, and estimate the health impact of air pollution, " says Mitchio Okumura, professor of chemical physics at Caltech and one of the principal investigators on the research. "This work demonstrates how important accurate laboratory measurements are to our understanding of the atmosphere," added JPL Senior Research Scientist Stanley P. Sander, who led that team's effort. The key reaction in question in this research is the reaction between nitrogen dioxide, NO2, and the hydroxyl radical, OH. In the presence of sunlight, these two, along with volatile organic compounds (VOCs), play important roles in the chemical reactions that form ozone.
TO READ THIS ARTICLE, CREATE YOUR ACCOUNT
And extend your reading, free of charge and with no commitment.
