A comparison of chemical mechanisms using tagged ozone production potential (TOPP) analysis
Item
Title (Dublin Core)
A comparison of chemical mechanisms using tagged ozone production potential (TOPP) analysis
Description (Dublin Core)
Ground-level ozone is a secondary pollutant produced photochemically from reactions of NO<sub><i>x</i></sub> with peroxy radicals produced during volatile organic compound (VOC) degradation. Chemical transport models use simplified representations of this complex gas-phase chemistry to predict O<sub>3</sub> levels and inform emission control strategies. Accurate representation of O<sub>3</sub> production chemistry is vital for effective prediction. In this study, VOC degradation chemistry in simplified mechanisms is compared to that in the near-explicit Master Chemical Mechanism (MCM) using a box model and by "tagging" all organic degradation products over multi-day runs, thus calculating the tagged ozone production potential (TOPP) for a selection of VOCs representative of urban air masses. Simplified mechanisms that aggregate VOC degradation products instead of aggregating emitted VOCs produce comparable amounts of O<sub>3</sub> from VOC degradation to the MCM. First-day TOPP values are similar across mechanisms for most VOCs, with larger discrepancies arising over the course of the model run. Aromatic and unsaturated aliphatic VOCs have the largest inter-mechanism differences on the first day, while alkanes show largest differences on the second day. Simplified mechanisms break VOCs down into smaller-sized degradation products on the first day faster than the MCM, impacting the total amount of O<sub>3</sub> produced on subsequent days due to secondary chemistry.
Creator (Dublin Core)
Coates, J.
Butler, T. M.
Date (Dublin Core)
2018-09-09
Type (Dublin Core)
Text
Format (Dublin Core)
application/pdf
Identifier (Dublin Core)
10.5194/acp-15-8795-2015
https://acp.copernicus.org/articles/15/8795/2015/
Source (Dublin Core)
eISSN: 1680-7324
Language (Dublin Core)
eng
