Preprints
https://doi.org/10.5194/acp-2021-605
https://doi.org/10.5194/acp-2021-605

  20 Jul 2021

20 Jul 2021

Review status: a revised version of this preprint was accepted for the journal ACP and is expected to appear here in due course.

Development and evaluation of a new compact mechanism for aromatic oxidation in atmospheric models

Kelvin Bates1,2, Daniel Jacob1, Ke Li3, Peter Ivatt4,5, Mat Evans4,5, Yingying Yan6, and Jintai Lin7 Kelvin Bates et al.
  • 1School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
  • 2Department of Environmental Toxicology, University of California at Davis, Davis, CA, USA
  • 3School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing, China
  • 4Wolfson Atmospheric Chemistry Laboratories, Department of Chemistry, University of York, York, UK
  • 5National Centre for Atmospheric Science, Department of Chemistry, University of York, York, UK
  • 6Department of Atmospheric Sciences, School of Environmental Studies, China University of Geosciences (Wuhan), Wuhan, China
  • 7Laboratory for Climate and Ocean–Atmosphere Studies, Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing, China

Abstract. Aromatic hydrocarbons (mainly benzene, toluene, and xylenes) play an important role in atmospheric chemistry but the associated chemical mechanisms are complex and uncertain. Spare representation of this chemistry in models is needed for computational tractability. Here we develop a new compact mechanism for aromatic chemistry (GC13) that captures current knowledge from laboratory and computational studies with only 17 unique species and 44 reactions. We compare GC13 to six other currently used mechanisms of varying complexity in box model simulations of environmental chamber data and diurnal boundary layer chemistry, and show that GC13 provides results consistent with or better than more complex mechanisms for oxygenated products (alcohols, carbonyls, dicarbonyls), ozone, and hydrogen oxide (HOx ≡ OH + HO2) radicals. GC13 features in particular increased radical recycling and increased ozone destruction from phenoxy-phenylperoxy radical cycling relative to other mechanisms. We implement GC13 into the GEOS-Chem global chemical transport model and find higher glyoxal yields and net ozone loss from aromatic chemistry compared to other mechanisms. Aromatic oxidation in the model contributes 23 %, 5 %, and 8 % of global glyoxal, methylglyoxal, and formic acid production respectively, and has mixed effects on formaldehyde. It drives small decreases in global tropospheric OH (−2.2 %), NOx (≡ NO + NO2; −3.7 %) and ozone (−0.8 %), but a large increase in NO3 (+22 %) from phenoxy-phenylperoxy radical cycling. Regional effects in polluted environments can be substantially larger, especially from photolysis of carbonyls produced by aromatic oxidation, which drives large wintertime increases in OH and ozone concentrations.

Kelvin Bates et al.

Status: closed

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on acp-2021-605', Anonymous Referee #1, 21 Sep 2021
  • RC2: 'Comment on acp-2021-605', Anonymous Referee #2, 24 Sep 2021
  • AC1: 'Author responses to referee comments', K.H. Bates, 05 Nov 2021

Status: closed

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on acp-2021-605', Anonymous Referee #1, 21 Sep 2021
  • RC2: 'Comment on acp-2021-605', Anonymous Referee #2, 24 Sep 2021
  • AC1: 'Author responses to referee comments', K.H. Bates, 05 Nov 2021

Kelvin Bates et al.

Kelvin Bates et al.

Viewed

Total article views: 689 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
478 200 11 689 80 5 13
  • HTML: 478
  • PDF: 200
  • XML: 11
  • Total: 689
  • Supplement: 80
  • BibTeX: 5
  • EndNote: 13
Views and downloads (calculated since 20 Jul 2021)
Cumulative views and downloads (calculated since 20 Jul 2021)

Viewed (geographical distribution)

Total article views: 709 (including HTML, PDF, and XML) Thereof 709 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 04 Dec 2021
Download
Short summary
Simple aromatic compounds (benzene, toluene, xylene) have complex gas-phase chemistry that is inconsistently represented in atmospheric models. We compile recent experimental and theoretical insights to develop a new mechanism for gas-phase aromatic oxidation that is sufficiently compact for use in multiscale models. We compare our new mechanism to chamber experiments and other mechanisms, and implement it in a global model to quantify the impacts of aromatic oxidation on tropospheric chemistry.
Altmetrics