Atmos. Chem. Phys. Discuss., 12, 14669-14695, 2012
www.atmos-chem-phys-discuss.net/12/14669/2012/
doi:10.5194/acpd-12-14669-2012
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under the Creative Commons Attribution 3.0 License.
Review Status
This discussion paper has been under review for the journal Atmospheric Chemistry and Physics (ACP). Please refer to the corresponding final paper in ACP.
Chamber simulation of photooxidation of dimethyl sulfide and isoprene in the presence of NOx
T. Chen and M. Jang
Department of Environmental Engineering Sciences, P.O. Box 116450, University of Florida, Gainesville, 32611 FL, USA

Abstract. In the kinetic model of this study, to advance the photooxidation of dimethyl sulfide (DMS) in the gas phase, the most recently reported reactions with their rate constants have been included. To improve the model predictability for the formation of sulfuric acid and methanesulfonic acid (MSA), heterogeneous reactions of gaseous DMS products (e.g., dimethyl sulfoxide (DMSO)) on the surface of aerosol have been included in the kinetic model. DMS was photoirradiated in the presence of NOx using a 2 m3 Teflon film chamber. The resulting chamber data was simulated using the new kinetic model. The model included in this study predicted that concentrations of both MSA and H2SO4 would significantly increase due to heterogeneous chemistry and this was well substantiated with experimental data. The model used in this study also predicted the decay of DMS, the formation of other gaseous products such as SO2, dimethyl sulfone (DMSO2), and the ozone formation linked to a NOx cycle. To study the effect of coexisting volatile organic compounds, the photooxidation of DMS in the presence of isoprene and NOx has been simulated using the new kinetic model integrated with the Master Chemical Mechanism (MCM) for isoprene oxidation, and compared to chamber data. Both the model simulation and the experimental data showed an increase in the yields of MSA and H2SO4 as the isoprene concentration increased.

Citation: Chen, T. and Jang, M.: Chamber simulation of photooxidation of dimethyl sulfide and isoprene in the presence of NOx, Atmos. Chem. Phys. Discuss., 12, 14669-14695, doi:10.5194/acpd-12-14669-2012, 2012.
 
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