Journal cover Journal topic
Atmospheric Measurement Techniques An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

IF value: 3.668
IF3.668
IF 5-year value: 3.707
IF 5-year
3.707
CiteScore value: 6.3
CiteScore
6.3
SNIP value: 1.383
SNIP1.383
IPP value: 3.75
IPP3.75
SJR value: 1.525
SJR1.525
Scimago H <br class='widget-line-break'>index value: 77
Scimago H
index
77
h5-index value: 49
h5-index49
Preprints
https://doi.org/10.5194/amt-2020-437
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/amt-2020-437
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

  06 Nov 2020

06 Nov 2020

Review status
This preprint is currently under review for the journal AMT.

The Improved Comparative Reactivity Method (ICRM): measurements of OH reactivity at high-NOX conditions in ambient air

Wenjie Wang1,3,, Jipeng Qi1,2,, Jun Zhou1,2, Bin Yuan1,2, Yuwen Peng1,2, Sihang Wang1,2, Jonathan Williams4, Vinayak Sinha5, and Min Shao1,2 Wenjie Wang et al.
  • 1Institute for Environmental and Climate Research, Jinan University, Guangzhou 511443, China
  • 2Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Guangzhou 511443, China
  • 3Multiphase Chemistry Department, Max Planck Institute for Chemistry, Mainz 55128, Germany
  • 4Atmospheric Chemistry Department, Max Planck Institute for Chemistry, Mainz 55128, Germany
  • 5Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research (IISER), Mohali 140306, India
  • These authors contributed equally to this work.

Abstract. The comparative reactivity method (CRM) has been developed more than a decade to measure OH reactivity (i.e. OH loss frequency) in both laboratory and field studies. However, accurate OH reactivity quantification remains challenging under real ambient condition, especially for OH reactivity measurements in high-NOX (e.g. > 10 ppbv) environments, as ambient NO enhance regeneration of OH radicals in the CRM reactor. To resolve this problem, we design a new improved CRM reactor (ICRM) and add NO into the system continuously, so that the HO2 radical concentration is suppressed. We confirmed the appropriate level of NO by determining the maximum decrease in the pyrrole level caused by regenerated OH radicals from NO + HO2. VOC-induced RO2 radicals in the ICRM reactor were also found to react with NO, which lead to the re-generation of OH radicals thus the underestimation of OH reactivity. This effect was quantified by the calibration of representative VOC species at different NO levels, and the correction coefficients obtained were used to correct the measured OH reactivity. All these efforts resulted in reducing the uncertainty of the NO-artifact correction by at least an order of magnitude compared to the original CRM system. Additionally, these technological improvements also considerably reduced the systematic errors from pyrrole photolysis that exists in the original system. A new operation mode was proposed for ICRM, which is able to avoid the interference resulting from OH radicals produced by photolysis of residual humidity and save time for ambient measurement. The ICRM system was employed in a field campaign to measure OH reactivity and performed well with ambient NO levels ranged from 0 to 50 ppbv, which were typically observed in urban and suburban atmosphere.

Wenjie Wang et al.

Interactive discussion

Status: open (until 01 Jan 2021)
Status: open (until 01 Jan 2021)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement

Wenjie Wang et al.

Wenjie Wang et al.

Viewed

Total article views: 78 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
53 24 1 78 11 3 3
  • HTML: 53
  • PDF: 24
  • XML: 1
  • Total: 78
  • Supplement: 11
  • BibTeX: 3
  • EndNote: 3
Views and downloads (calculated since 06 Nov 2020)
Cumulative views and downloads (calculated since 06 Nov 2020)

Viewed (geographical distribution)

Total article views: 138 (including HTML, PDF, and XML) Thereof 138 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 

Cited

Saved

No saved metrics found.

Discussed

No discussed metrics found.
Latest update: 29 Nov 2020
Publications Copernicus
Download
Short summary
We designed a new reactor for measurements of OH reactivity (i.e. OH radicals loss freqency) based on the comparative reactivity method work under the conditions with high NOx conditions, such as in cities. We performed a series laboratory tests to evaluate the new reactor to prove this. The new reactor was used in the field and performed well to measure OH reactivity in air influenced by upwind cities.
We designed a new reactor for measurements of OH reactivity (i.e. OH radicals loss freqency)...
Citation