Secondary organic aerosol (SOA) formation is considered in the framework of the gas/particle partitioning absorption model outlined by Pankow (1, 2). Expressions for the fractional SOA yield (Y) are developed within this framework and shown to be a function of the organic aerosol mass concentration, M o . These expressions are applied to over 30 individual reactive organic gas (ROG) photooxidation smog chamber experiments. Analysis of the data from these experiments clearly shows that Y is a strong function of M o and that secondary organic aerosol formation is best described by a gas/particle partitioning absorption model. In addition to the 30 individual ROG experiments, three experiments were performed with ROG mixtures. The expressions developed for Y in terms of M o , used in conjunction with the overall yield data from the individual ROG experiments, are able to account for the M o generated in the ROG mixture experiments. This observation not only suggests that SOA yields for individual ROGs are additive but that smog chamber SOA yield data may be confidently extrapolated to the atmosphere in order to determine the important ambient sources of SOA in the environment.

A series of sunlight-irradiated, smog-chamber experiments confirmed that the atmospheric organic aerosol formation potential of whole gasoline vapor cna be accounted for solely in terms of the aromatic fraction of the fuel. The total amount of secondary organic aerosol produced from the atmospheric oxidation of whole gasoline vapor can be represented as the sum of the contributions of the individual aromatic molecular constituents of the fuel. The urban atmospheric, anthropogenic hydrocarbon profile is approximated well by evaporated whole gasoline, and thus these results suggest that it is possible to model atmospheric secondary organic aerosol formation.

Secondary organic aerosol (SOA) yield curves have been obtained for 17 individual aromatic species from an extensive series of sunlight-irradiated smog chamber experiments. These yield curves, interpreted within the framework of a gas/aerosol absorption model, are used to quantitatively account for the SOA that is formed in a series of smog chamber experiments performed with the whole vapor of 12 different reformulated gasolines. The total amount of secondary organic aerosol produced from the atmospheric oxidation of whole gasoline vapor can be represented as the sum of the contributions of the individual aromatic molecular constituents of the fuel.

No abstract

No abstract