In the most polluted parts of Los Angeles—and on the most polluted days in those areas—current prediction models are underestimating ozone levels by between 5 to 10 percent. Researchers made this finding by fully characterizing a key chemical reaction that affects the formation of pollutants in smoggy air.
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.
The results 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 study coauthor Mitchio Okumura, professor of chemical physics at the California Institute of Technology (Caltech).Full story at Futurity.