Seasonal variations of C1-C4alkyl nitrates at a coastal site in Hong Kong: Influence of photochemical formation and oceanic emissions

Junwei Song, Yingyi Zhang, Yu Huang, Kin Fai Ho, Zibing Yuan, Zhenhao Ling, Xiaojun Niu, Yuan Gao, Long Cui, Peter K.K. Louie, Shuncheng Lee, Senchao Lai

Research output: Journal article publicationJournal articleAcademic researchpeer-review

6 Citations (Scopus)

Abstract

Five C 1-C 4 alkyl nitrates (RONO 2) were measured at a coastal site in Hong Kong in four selected months of 2011 and 2012. The total mixing ratios of C 1-C 4 RONO 25RONO 2) ranged from 15.4 to 143.7 pptv with an average of 65.9 ± 33.0 pptv. C 3-C 4 RONO 2 (2-butyl nitrate and 2-propyl nitrate) were the most abundant RONO 2 during the entire sampling period. The mixing ratios of C 3-C 4 RONO 2 were higher in winter than those in summer, while the ones of methyl nitrate (MeONO 2) were higher in summer than those in winter. Source analysis suggests that C 2-C 4 RONO 2 were mainly derived from photochemical formation along with biomass burning (58.3–71.6%), while ocean was a major contributor to MeONO 2 (53.8%) during the whole sampling period. The photochemical evolution of C 2-C 4 RONO 2 was investigated, and found to be dominantly produced by the parent hydrocarbon oxidation. The notable enrichment of MeONO 2 over C 3-C 4 RONO 2 was observed in a summer episode when the air masses originating from the South China Sea (SCS) and MeONO 2 was dominantly derived from oceanic emissions. In order to improve the accuracy of ozone (O 3) prediction in coastal environment, the relative contribution of RONO 2 from oceanic emissions versus photochemical formation and their coupling effects on O 3 production should be taken into account in future studies.

Original languageEnglish
Pages (from-to)275-284
Number of pages10
JournalChemosphere
Volume194
DOIs
Publication statusPublished - 1 Mar 2018

Keywords

  • Alkyl nitrates
  • Marine emissions
  • Ozone
  • Photochemical production
  • Seasonality

ASJC Scopus subject areas

  • Chemistry(all)
  • Environmental Chemistry

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