摘要:

The influence of second-generation products on the particle mass yield of beta-caryophyllene ozonolysis was systematically tested and quantified. The approach was to vary the relative concentrations of first- and second-generation products by adjusting the concentration of ozone while observing changes in particle mass yield. For all wall-loss corrected organic particle mass concentrations M-org of this study (0.5 < M-org < 230 mu g m(-3)), the data show that the particle-phase organic material was composed for the most part of second-generation products. For 0.5 < M-org < 10 mu g m(-3), a range which overlaps with atmospheric concentrations, the particle mass yield was 10 to 20% and was not sensitive to ozone exposure, implying that the constituent molecules were rapidly produced at all investigated ozone exposures. In contrast, for M-org > 10 mu g m(-3) the particle mass yield increased to as high as 70% for the ultimate yield corresponding to the greatest ozone exposures. These differing dependencies on ozone exposure under different regimes of M-org are explained by a combination of the ozonolysis lifetimes of the first-generation products and the volatility distribution of the resulting second-generation products. First-generation products that have short lifetimes produce low-volatility second-generation products whereas first-generation products that have long lifetimes produce high-volatility second-generation products. The ultimate particle mass yield was defined by mass-based stoichiometric yields alpha(i) of alpha(0) = 0.17 +/- 0.05, alpha(1) = 0.11 +/- 0.17, and alpha(2) = 1.03 +/- 0.30 for corresponding saturation concentrations of 1, 10, and 100 mu g m(-3). Terms alpha(0) and alpha(1) had low sensitivity to the investigated range of ozone exposure whereas term alpha(2) increased from 0.32 +/- 0.13 to 1.03 +/- 0.30 as the ozone exposure was increased. These findings potentially allow for simplified yet accurate parameterizations in air quality and climate models that seek to represent the ozonolysis particle mass yields of certain classes of biogenic compounds.

附注:

ISI Document Delivery No.: 926BQTimes Cited: 0Cited Reference Count: 68Chen, Q. Li, Y. L. McKinney, K. A. Kuwata, M. Martin, S. T.Office of Science (BES), US Department of Energy[DE-FG02-08ER64529]; NASA; Hong Kong University of Science and Technology; Research Grants Council of the Hong Kong Special Administrative Region, China[610909]; Japan Society for the Promotion of ScienceThis material is based upon work supported by the Office of Science (BES), US Department of Energy, Grant No. DE-FG02-08ER64529. Q. C. acknowledges support from the NASA Earth and Space Science Fellowship. Y. J. L. acknowledges support from the Hong Kong University of Science and Technology Overseas Research Award and the Research Grants Council of the Hong Kong Special Administrative Region, China (Project No. 610909). M. K. acknowledges support from the Japan Society for the Promotion of Science Postdoctoral Fellowship. The authors thank Amanda Mifflin and Mackenzie Smith for their assistance with the experiments. The authors thank Adam Bateman and Soeren Zorn for helpful discussion.Copernicus gesellschaft mbhGottingen