Model–measurement comparison of functional group abundance in α-pinene and 1,3,5-trimethylbenzene secondary organic aerosol formation
Item
Title (Dublin Core)
Model–measurement comparison of functional group abundance in α-pinene and 1,3,5-trimethylbenzene secondary organic aerosol formation
Description (Dublin Core)
Secondary organic aerosol (SOA) formed by <i>α</i>-pinene and 1,3,5-trimethylbenzene photooxidation under different NO<sub>x</sub> regimes is simulated using the Master Chemical Mechanism v3.2 (MCM) coupled with an absorptive gas–particle partitioning module. Vapor pressures for individual compounds are estimated with the SIMPOL.1 group contribution model for determining apportionment of reaction products to each phase. We apply chemoinformatic tools to harvest functional group (FG) composition from the simulations and estimate their contributions to the overall oxygen to carbon ratio. Furthermore, we compare FG abundances in simulated SOA to measurements of FGs reported in previous chamber studies using Fourier transform infrared spectroscopy. These simulations qualitatively capture the dynamics of FG composition of SOA formed from both <i>α</i>-pinene and 1,3,5-trimethylbenzene in low-NO<sub>x</sub> conditions, especially in the first hours after start of photooxidation. Higher discrepancies are found after several hours of simulation; the nature of these discrepancies indicates sources of uncertainty or types of reactions in the condensed or gas phase missing from current model implementation. Higher discrepancies are found in the case of <i>α</i>-pinene photooxidation under different NO<sub>x</sub> concentration regimes, which are reasoned through the domination by a few polyfunctional compounds that disproportionately impact the simulated FG abundance in the aerosol phase. This manuscript illustrates the usefulness of FG analysis to complement existing methods for model–measurement evaluation.
Creator (Dublin Core)
Ruggeri, Giulia
Bernhard, Fabian A.
Henderson, Barron H.
Takahama, Satoshi
Date (Dublin Core)
2018-09-08
Type (Dublin Core)
Text
Format (Dublin Core)
application/pdf
Identifier (Dublin Core)
10.5194/acp-16-8729-2016
https://acp.copernicus.org/articles/16/8729/2016/
Source (Dublin Core)
eISSN: 1680-7324
Language (Dublin Core)
eng
