Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
https://doi.org/10.5194/acp-2016-1159
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
06 Jan 2017
Review status
A revision of this discussion paper was accepted for the journal Atmospheric Chemistry and Physics (ACP) and is expected to appear here in due course.
Comprehensive Atmospheric Modeling of Reactive Cyclic Siloxanes and Their Oxidation Products
Nathan J. Janechek1,2, Kaj M. Hansen3, and Charles O. Stanier1,2 1Department of Chemical and Biochemical Engineering, University of Iowa, Iowa City, IA 52242, USA
2IIHR Hydroscience and Engineering, University of Iowa, Iowa City, IA 52242, USA
3Department of Environmental Science, Aarhus University, Roskilde, Denmark
Abstract. Cyclic volatile methyl siloxanes (cVMS) are important components in personal care products that transport and react in the atmosphere. Octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), dodecamethylcyclohexasiloxane (D6), and their gas phase oxidation products have been incorporated into the Community Multiscale Air Quality (CMAQ) model. Gas phase oxidation products, as the precursor to secondary organic aerosol from this compound class, were included to quantify the maximum potential for aerosol formation from gas phase reactions with OH. Four 1-month periods were modeled to quantify typical concentrations, seasonal variability, spatial patterns, and vertical profiles. Typical model concentrations showed parent compounds were highly dependent on population density as cities had monthly averaged peak D5 concentrations up to 432 ng m−3. Peak oxidized D5 concentrations were significantly less, up to 9 ng m−3 and were located downwind of major urban areas. Model results were compared to available measurements and previous simulation results. Seasonal variation was analyzed and differences in seasonal influences were observed between urban and rural locations. Parent compound concentrations in urban and peri-urban locations were sensitive to transport factors, while parent compounds in rural areas and oxidized product concentrations were influenced by large-scale seasonal variability in OH.

Citation: Janechek, N. J., Hansen, K. M., and Stanier, C. O.: Comprehensive Atmospheric Modeling of Reactive Cyclic Siloxanes and Their Oxidation Products, Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2016-1159, in review, 2017.
Nathan J. Janechek et al.
Interactive discussionStatus: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version      Supplement - Supplement
 
RC1: 'Janechek et al.', Anonymous Referee #1, 05 Feb 2017 Printer-friendly Version 
 
RC2: 'Anonymous Reviewer #2', Anonymous Referee #2, 22 Feb 2017 Printer-friendly Version 
 
AC1: 'Authors’ Response', Nathan Janechek, 16 Apr 2017 Printer-friendly Version Supplement 
Nathan J. Janechek et al.
Nathan J. Janechek et al.

Viewed

Total article views: 402 (including HTML, PDF, and XML)

HTML PDF XML Total Supplement BibTeX EndNote
279 79 44 402 97 16 43

Views and downloads (calculated since 06 Jan 2017)

Cumulative views and downloads (calculated since 06 Jan 2017)

Viewed (geographical distribution)

Total article views: 402 (including HTML, PDF, and XML)

Thereof 398 with geography defined and 4 with unknown origin.

Country # Views %
  • 1

Saved

Discussed

Latest update: 24 Jun 2017
Publications Copernicus
Download
Short summary
Gas phase cyclic volatile methyl siloxanes and their oxidation products, which are likely precursors to secondary organic aerosol, were modeled using an atmospheric transport model over North America. Typical concentrations, spatial patterns, seasonal variability, and vertical profiles were quantified. Urban parent compound concentrations were sensitive to transport factors while rural parent and oxidized product concentrations were sensitive to large-scale seasonal variability in OH.
Gas phase cyclic volatile methyl siloxanes and their oxidation products, which are likely...
Share