National Exposure Research Laboratory, US Environmental Protection Agency , Research Triangle Park, North Carolina, 27711 United States.
Environ Sci Technol. 2013 Oct 1;47(19):11056-64. doi: 10.1021/es402106h. Epub 2013 Sep 11.
Isoprene significantly contributes to organic aerosol in the southeastern United States where biogenic hydrocarbons mix with anthropogenic emissions. In this work, the Community Multiscale Air Quality model is updated to predict isoprene aerosol from epoxides produced under both high- and low-NOx conditions. The new aqueous aerosol pathways allow for explicit predictions of two key isoprene-derived species, 2-methyltetrols and 2-methylglyceric acid, that are more consistent with observations than estimates based on semivolatile partitioning. The new mechanism represents a significant source of organic carbon in the lower 2 km of the atmosphere and captures the abundance of 2-methyltetrols relative to organosulfates during the simulation period. For the parametrization considered here, a 25% reduction in SOx emissions effectively reduces isoprene aerosol, while a similar reduction in NOx leads to small increases in isoprene aerosol.
异戊二烯是美国东南部有机气溶胶的主要贡献者，在那里，生物源碳氢化合物与人为排放物混合。在这项工作中，我们更新了社区多尺度空气质量模型，以预测在高低氮氧化物条件下生成的环氧化物产生的异戊二烯气溶胶。新的水相气溶胶途径可以明确预测两种关键的异戊二烯衍生物种，即 2-甲基四醇和 2-甲基甘油酸，它们比基于半挥发性分配的估计更符合观测结果。新机制代表了大气低层（0-2 公里）中有机碳的一个重要来源，并且在模拟期间捕获了 2-甲基四醇相对于有机硫酸盐的丰度。对于这里考虑的参数化，SOx 排放量减少 25%可有效减少异戊二烯气溶胶，而 NOx 排放量类似减少则会导致异戊二烯气溶胶略有增加。
