Airborne determination of the temporo-spatial distribution of benzene, toluene, nitrogen oxides and ozone in the boundary layer across Greater London, UK
Airborne determination of the temporo-spatial distribution of benzene, toluene, nitrogen oxides and ozone in the boundary layer across Greater London, UK
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DOI：
10.5194/acp-15-5083-2015
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发表时间：
2014-10
影响因子：
6.3
通讯作者：
M. Shaw;James D. Lee;B. Davison;A. Vaughan;R. Purvis;A. Harvey;A. Lewis;C. Hewitt
中科院分区：
文献类型：
--
作者：
M. Shaw;James D. Lee;B. Davison;A. Vaughan;R. Purvis;A. Harvey;A. Lewis;C. Hewitt
抽象的。2013年6月24日至7月9日期间，使用Dornier 228飞机在大伦敦上空的大气边界层中测量了苯和甲苯、氮氧化物（NOx）和臭氧（O3）的高空间分辨混合比。采用质子转移反应质谱仪（PTR-MS）原位测定甲苯和苯，双通道NOx化学发光法测定NOx，紫外吸收法测定O3混合比。在内伦敦上空360 ± 10 m a.g.l.观测到的平均混合比苯、甲苯、NO、NO2和NOx的平均浓度分别为0.20 ± 0.05、0.28 ± 0.07、13.2 ± 8.6、21.0 ± 7.3和34.3 ± 15.2 ppbv。NO2，苯和甲苯的混合比例之间的线性回归分析产生了很强的协方差，表明这些化合物主要是共享相同或共同位于城市内的来源。在360 ± 10 m a.g.l.处测量的平均混合比。外伦敦上空的温度总是低于内伦敦上空的温度。在交通密度最高的地方，甲苯/苯（T / B）浓度比最高（平均为1.8 ± 0.5 ppbv ppbv-1），表明当地污染源很强。NOx、苯和甲苯混合比的日间最大值出现在上午（约40 ppbv NOx、约350 pptv甲苯和约200 pptv苯），臭氧混合比的日间最大值出现在下午中段（约40 ppbv O3），均在360 ± 10 m a.g.l.。
Abstract. Highly spatially resolved mixing ratios of benzene and toluene, nitrogen oxides (NOx) and ozone (O3) were measured in the atmospheric boundary layer above Greater London during the period 24 June to 9 July 2013 using a Dornier 228 aircraft. Toluene and benzene were determined in situ using a proton transfer reaction mass spectrometer (PTR-MS), NOx by dual-channel NOx chemiluminescence and O3 mixing ratios by UV absorption. Average mixing ratios observed over inner London at 360 ± 10 m a.g.l. were 0.20 ± 0.05, 0.28 ± 0.07, 13.2 ± 8.6, 21.0 ± 7.3 and 34.3 ± 15.2 ppbv for benzene, toluene, NO, NO2 and NOx respectively. Linear regression analysis between NO2, benzene and toluene mixing ratios yields a strong covariance, indicating that these compounds predominantly share the same or co-located sources within the city. Average mixing ratios measured at 360 ± 10 m a.g.l. over outer London were always lower than over inner London. Where traffic densities were highest, the toluene / benzene (T / B) concentration ratios were highest (average of 1.8 ± 0.5 ppbv ppbv-1), indicative of strong local sources. Daytime maxima in NOx, benzene and toluene mixing ratios were observed in the morning (~ 40 ppbv NOx, ~ 350 pptv toluene and ~ 200 pptv benzene) and in the mid-afternoon for ozone (~ 40 ppbv O3), all at 360 ± 10 m a.g.l.