Observations of N2O5and ClNO2at a polluted urban surface site in North China: High N2O5uptake coefficients and low ClNO2product yields

Xinfeng Wang, Hao Wang, Likun Xue, Tao Wang, Liwei Wang, Rongrong Gu, Weihao Wang, Yee Jun Tham, Zhe Wang, Lingxiao Yang, Jianmin Chen, Wenxing Wang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

51 Citations (Scopus)

Abstract

To understand the abundances and chemistry of N2O5and ClNO2in the polluted urban atmosphere in North China, field measurements were conducted by deploying a chemical ionization mass spectrometer in urban Ji'nan in September 2014. The observed surface N2O5concentrations were relatively low, with an average nocturnal value of 22 pptv, although the source of NO3was rather strong, i.e., the NO2and O3were at very high levels. The N2O5concentration peaked in the early evening, which was associated with thermal power plant plumes and residual O3. Nocturnal N2O5was lost very rapidly, mainly through heterogeneous reactions on aerosol surfaces. The estimated N2O5uptake coefficient was in the range of 0.042–0.092, among the highest values obtained from ground based field measurements. The fast heterogeneous reaction of N2O5on high loadings of aerosols generated relatively high levels of ClNO2,with an average nocturnal concentration of 132 pptv. Despite the rich chloride content in aerosols, the ClNO2product yield was low, 0.014 and 0.082 in two nighttime cases, much lower than the calculated values from the experiment-derived parameterization. The suppressed chlorine activation in polluted urban atmospheres was possibly associated with the reduced hygroscopicity, solubility, and activity of chloride in complex ambient aerosols.
Original languageEnglish
Pages (from-to)125-134
Number of pages10
JournalAtmospheric Environment
Volume156
DOIs
Publication statusPublished - 1 Jan 2017

Keywords

  • Dinitrogen pentoxide
  • Nitryl chloride
  • Product yield
  • Uptake coefficient
  • Urban China

ASJC Scopus subject areas

  • Environmental Science(all)
  • Atmospheric Science

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