DOI: 10.1016/j.atmosenv.2014.09.063
Scopus记录号: 2-s2.0-84907704459
论文题名: Analysis of diurnal variability of atmospheric halocarbons and CFC replacements to imply emission strength and sources at an urban site of Lukang in central Taiwan
作者: Lee B ; -S ; , Chiou C ; -B ; , Lin C ; -Y
刊名: Atmospheric Environment
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2014
卷: 99 起始页码: 112
结束页码: 123
语种: 英语
英文关键词: CFC replacements
; Diurnal variability
; Enhancement
; Halocarbons
; Lukang
Scopus关键词: Halocarbons
; CFC replacements
; Diurnal variability
; Emission strength
; Lukang
; Urban site
; Image enhancement
; bromochlorodifluoromethane
; carbon tetrachloride
; chlorodifluoromethane
; dichlorodifluoromethane
; dichloromethane
; halide
; halocarbon
; trichloroethylene
; trichlorofluoromethane
; unclassified drug
; air temperature
; atmospheric chemistry
; CFC
; diurnal variation
; environmental quality
; halocarbon
; traffic emission
; urban atmosphere
; air pollution
; Article
; carbon footprint
; meteorology
; Taiwan
; urban area
; Lukang
; Taiwan
Scopus学科分类: Environmental Science: Water Science and Technology
; Earth and Planetary Sciences: Earth-Surface Processes
; Environmental Science: Environmental Chemistry
英文摘要: Hourly atmospheric measurements of halocarbons and chlorofluorocarbon (CFC) replacements were conducted at an urban site of Lukang, Changhua, in central Taiwan from May to August, 2013. The temporal distribution of different groups of halocarbons in the Lukang urban atmosphere, including chlorofluorocarbons (CFCs), Chlorodifluoromethane (HCFC-22), Bromochlorodifluoromethane (Halon-1211), and other chlorinated compounds, is presented and discussed. The concentrations (mixing ratios) of HCFC-22, Dichlorodifluoromethane (CFC-12), Halon-1211, Trichlorofluoromethane (CFC-11), Dichloromethane (CH2Cl2), and Trichloroethylene (TCE) were enhanced with respect to the local background levels; the atmospheric mixing ratio of carbon tetrachloride (CCl4) was slightly higher than its local background level; on the other hand, 1,1,2-Trichlorotrifluoroethane (CFC-113) was relatively uniform and not very different from background atmospheric level in non-urban areas. Among these compounds, HCFC-22, Halon-1211 and the halogenated compounds, CH2Cl2 and TCE, used as solvents were strongly enhanced. The average mixing ratio of Halon-1211 was higher than the local background of ~4.5ppt by ~60% although Halon-1211 production had been phased out by 1996.Hourly average mixing ratios of halocarbons (HCFC-22, CFC-12, Halon-1211, CFC-11, CH2Cl2, and TCE) illustrated a distinct diurnal cycle characterized with a pattern of elevated mixing ratio and large mixing ratio variability amplitude at night relative to that in daytime. Although emission sources of these halocarbons were complex, hourly average mixing ratios for most of these high variability halocarbons peaked at ~5:00 AM when the hourly average wind speed reached the minimum value of the day; by contrast, the hourly average mixing ratio of CO peaked at ~8:30 AM when the ambient atmospheric wind condition was strongly influenced by sea breezes during the traffic rush hours. This phenomenon revealed that meteorological factors predominated the distribution of halocarbon mixing ratio in the urban atmosphere and the traffic emission of CFC-12 derived from old vehicles manufactured before 1994 was insignificant to the CFC-12 mixing ratio in the urban atmosphere. The meteorological condition of nighttime atmospheric temperature inversion and low wind speed facilitated the accumulation of terrestrial airborne pollutants near the ground; consequently the hourly average mixing ratios at night were higher than those in daytime by up to ~2% (CFC-11), ~7% (CFC-12), ~75% (HCFC-22), ~72% (Halon-1211), ~280% (CH2Cl2), and ~155% (TCE). © 2014. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/80493
Appears in Collections: 气候变化事实与影响
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作者单位: Department of Landscape Architecture, Chung Chou University of Science and Technology, Yuanlin, Changhua, Taiwan; Department of Mechanical and Automation Engineering, Chung Chou University of Science and Technology, Yuanlin, Changhua 510, Taiwan
Recommended Citation:
Lee B,-S,, Chiou C,et al. Analysis of diurnal variability of atmospheric halocarbons and CFC replacements to imply emission strength and sources at an urban site of Lukang in central Taiwan[J]. Atmospheric Environment,2014-01-01,99