| Title: | Vertical characteristics of VOCs in the lower troposphere over the North China Plain during pollution periods |
| Author(s): | Sun J; Wang Y; Wu F; Tang G; Wang L; Wang Y; Yang Y; |
| Address: | "LAPC, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100191, China; Institute of Atmospheric Physics, Center of Technical Support and Service, China. LAPC, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100191, China. Electronic address: wys@dq.cern.ac.cn. LAPC, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100191, China" |
| DOI: | 10.1016/j.envpol.2017.10.051 |
| ISSN/ISBN: | 1873-6424 (Electronic) 0269-7491 (Linking) |
| Abstract: | "In recent years, photochemical smog and gray haze-fog have frequently appeared over northern China. To determine the spatial distribution of volatile organic compounds (VOC) during a pollution period, tethered balloon flights were conducted over a suburban site on the North China Plain. Statistical analysis showed that the VOCs concentrations peaked at the surface, and decreased with altitude. A rapid decrease appeared from the surface to 400 m, with concnetrations of alkanes, alkenes, aromatics and halocarbons decreasing by 48.0%, 53.3%, 43.3% and 51.1%, respectively. At heights in the range of 500-1000 m, alkenes concnetrations decline by 40.2%; alkanes and halocarbons concnetrations only decreased by 24.8% and 6.4%, respectively; and aromatics increased slightly by 5.5%. High concentrations VOCs covered a higher range of height (400 m) on heavy pollution days due to lacking of diffusion power. The VOCs concentrations decreased by 50% at 200 m on light pollution days. The transport of air mass affected the composition and concentration of high-altitude VOCs, especially on lightly polluted days. These air masses originated in areas with abundant traffic and combustion sources. Reactive aromatics (k(OH)>20,000 ppm(-1) min(-1) and k(OH)<20,000 ppm(-1) min(-1)) were the main contributor to the ozone formation, accounting for 37%, on the surface on light pollution days. The contribution increased to 52% with pollution aggravated, and increased to 64% with height. The contributions of reactive aromatics were influenced by the degree of air mass aging. Under the umbrella of aging air mass, the contribution of reactive aromatics increased with height" |
| Keywords: | Air Pollutants/*analysis Alkanes/analysis China Environmental Monitoring Ozone/analysis Volatile Organic Compounds/*analysis Ozone formation potential (OFP) Pollution VOCs Vertical profiles; |
| Notes: | "MedlineSun, Jie Wang, Yuesi Wu, Fangkun Tang, Guiqian Wang, Lili Wang, Yinghong Yang, Yuan eng England 2017/11/22 Environ Pollut. 2018 May; 236:907-915. doi: 10.1016/j.envpol.2017.10.051. Epub 2017 Nov 20" |
