Vertical distributions of non-methane hydrocarbons and halocarbons in the lower troposphere over northeast China

Likun Xue, Tao Wang, Isobel J. Simpson, Aijun Ding, Jian Gao, Donald R. Blake, Xuezhong Wang, Wenxing Wang, Hengchi Lei, Dezhen Jin

Research output: Journal article publicationJournal articleAcademic researchpeer-review

22 Citations (Scopus)

Abstract

Vertical distributions of air pollutants are crucial for understanding the key processes of atmospheric transport and for evaluating chemical transport models. In this paper, we present measurements of non-methane hydrocarbons (NMHCs) and halocarbons obtained from an intensive aircraft study over northeast (NE) China in summer 2007. Most compounds exhibited a typical negative profile of decreasing mixing ratios with increasing altitude, although the gradients differed with different species. Three regional plumes with enhanced VOC mixing ratios were discerned and characterized. An aged plume transported from the northern part of the densely populated North China Plain (NCP; i.e. Beijing-Tianjin area) showed relatively higher levels of HCFC-22, 1,2-dichloroethane (1,2-DCE) and toluene. In comparison, the plume originating from Korea had higher abundances of CFC-12, tetrachloroethene (C2Cl4) and methyl chloride (CH3Cl), while regional air masses from NE China contained more abundant light alkanes. By comparing these results with the earlier PEM-West B (1994) and TRACE-P (2001) aircraft measurements, continuing declining trends were derived for methyl chloroform (CH3CCl3), tetrachloromethane (CCl4) and C2Cl4over the greater China-northwestern Pacific region, indicating the accomplishment of China in reducing these compounds under the Montreal protocol. However, the study also provided evidence for the continuing emissions of several halocarbons in China in 2007, such as CFCs (mainly from materials in stock) and HCFCs.
Original languageEnglish
Pages (from-to)6501-6509
Number of pages9
JournalAtmospheric Environment
Volume45
Issue number36
DOIs
Publication statusPublished - 1 Nov 2011

Keywords

  • Aircraft study
  • Halocarbon
  • NE China
  • Non-methane hydrocarbon
  • Regional plume
  • Vertical distribution

ASJC Scopus subject areas

  • Environmental Science(all)
  • Atmospheric Science

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