Open AccessBox model studies of the secondary organic aerosol formation under different HC/NO x conditions using the subset of the Master Chemical Mechanism for α ‐pinene oxidation
Author(s) -
Xia Adam G.,
Michelangeli Diane V.,
Makar Paul A.
Publication year - 2008
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2007jd008726
Subject(s) - aerosol , pinene , mass concentration (chemistry) , chemistry , box model , environmental chemistry , chemical composition , mass fraction , analytical chemistry (journal) , atmospheric sciences , organic chemistry , geology
A subset of a near‐explicit Master Chemical Mechanism (v3.1) describing α ‐pinene oxidation (976 reactions and 331 compounds) coupled with a gas/particle absorptive partitioning model is used as a benchmark for the study of secondary organic aerosol (SOA) formation within a box model under atmospheric relevant conditions of averaged HC/NO x ratios between 0.18 and 8.43 (ppbvC/ppbv). Results from the detailed mechanism for α ‐pinene oxidation show that total SOA mass increases as the HC/NO x ratio increases within the studied range. The mass of peroxynitrates and the nitrates in the aerosol phase increases with increasing HC/NO x ratio, despite decreases in the total (gas plus aerosol) mass of these species, because of increases in mass of organic peroxides and acids in these conditions. The fractional composition of aerosol mass indicates organic peroxides and acids dominate at high HC/NO x ratios and peroxynitrates and nitrates dominate at low HC/NO x ratios. In addition, 28 out of 149 condensable products are identified as important compounds for SOA formation. Of the organic nitrates, only two contribute consistently to organic aerosol mass. Organic peroxide and acid mass in the aerosol phase is distributed over a larger number of species. The 28 species identified here are suitable targets for future laboratory and field analysis of organic aerosols and are recommended for use in future mechanism reduction work.