Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 5.668 IF 5.668
  • IF 5-year value: 6.201 IF 5-year
  • CiteScore value: 6.13 CiteScore
  • SNIP value: 1.633 SNIP 1.633
  • IPP value: 5.91 IPP 5.91
  • SJR value: 2.938 SJR 2.938
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 174 Scimago H
    index 174
  • h5-index value: 87 h5-index 87
Discussion papers
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.

Submitted as: research article 03 Jun 2019

Submitted as: research article | 03 Jun 2019

Review status
This discussion paper is a preprint. It is a manuscript under review for the journal Atmospheric Chemistry and Physics (ACP).

Estimation of NOx and SO2 Emissions from Sarnia, Ontario using Mobile-MAX-DOAS and a NOx-Analyzer

Zoe Y. W. Davis1, Sabour Baray2, Chris A. McLinden3, Aida Khanbabakhani2, William Fujs2, Csilla Csukat2, Jerzy Debosz4, and Robert McLaren2 Zoe Y. W. Davis et al.
  • 1Graduate Program in Earth and Space Science, York University, Toronto, M3J 1P3, Canada
  • 2Centre for Atmospheric Chemistry, York University, Toronto, M3J 1P3, Canada
  • 3Environnment and Climate Change Canada, Toronto, M3H 5T4, Canada
  • 4Air Quality Monitoring and Assessment Unit, Ontario Ministry of the Environment, Conservation and Parks, Etobicoke, M9P 3V6, Canada

Abstract. Sarnia, ON experiences pollutant emissions disproportionate to its relatively small size. The small size of the city limits traditional top-down emission estimate techniques (e.g., satellite) but a low-cost solution for emission monitoring is Mobile-MAX-DOAS. Measurements were made using this technique from 21/03/2017 to 23/03/2017 along various driving routes to retrieve vertical column densities (VCDs) of NO2 and SO2 and to estimate emissions of NOx and SO2 from the Sarnia region. A novel aspect of the current study was the installation of a NOx analyzer in the vehicle to allow real time measurement and characterization of near-surface NOx/NO2 ratios across the urban plumes, allowing improved accuracy of NOx emission estimates. Confidence in the use of near-surface measured NOx/NO2 ratios for estimation of NOx emissions was increased by relatively well-mixed boundary layer conditions. These conditions were indicated by similar temporal trends in NO2 VCDs and mixing ratios when measurements were sufficiently distant from the sources. Leighton ratios within transported plumes indicated peroxy radicals were likely disturbing the NO-NO2-O3 photostationary state through VOC oxidation. The average lower limit emission estimate of NOx from Sarnia was 1.60 ± 0.34 tonnes hr−1 using local 10 m elevation wind-speed measurements. Our estimates were larger than the downscaled annual 2017 NPRI reported industrial emissions of 0.9 tonnes NOx hr−1. Our lower limit estimate of SO2 emissions from Sarnia was 1.81 ± 0.83 tonnes SO2 hr−1, equal within uncertainty to the 2017 NPRI downscaled value of 1.85 tonnes SO2 hr−1. Satellite-derived NO2 VCDs over Sarnia from the Ozone Monitoring Instrument (OMI) were lower than Mobile-MAX-DOAS VCDs, likely due to the large pixel size relative to the city’s size. The results of this study support the utility of the Mobile-MAX-DOAS method for estimating NOx and SO2 emissions in relatively small, highly industrialized regions especially when supplemented with mobile NOx measurements.

Zoe Y. W. Davis et al.
Interactive discussion
Status: open (extended)
Status: open (extended)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement
Zoe Y. W. Davis et al.
Zoe Y. W. Davis et al.
Total article views: 218 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
173 43 2 218 11 0 3
  • HTML: 173
  • PDF: 43
  • XML: 2
  • Total: 218
  • Supplement: 11
  • BibTeX: 0
  • EndNote: 3
Views and downloads (calculated since 03 Jun 2019)
Cumulative views and downloads (calculated since 03 Jun 2019)
Viewed (geographical distribution)  
Total article views: 139 (including HTML, PDF, and XML) Thereof 138 with geography defined and 1 with unknown origin.
Country # Views %
  • 1
No saved metrics found.
No discussed metrics found.
Latest update: 21 Aug 2019
Publications Copernicus
Short summary
In this paper, we describe the use of mobile vehicle mounted instrumentation to measure pollutants both at the surface and overhead (via a telescope) that are coming from a source. This allows us to calculate the total emissions from the source, in this case the city of Sarnia, ON, including both industrial emissions and emissions from the city populace. In this paper we talk about improvements to the technique in the form of extra instrumentation in the vehicle.
In this paper, we describe the use of mobile vehicle mounted instrumentation to measure...