Fine carbonaceous aerosol characteristics at a megacity during the Chinese Spring Festival as given by OC/EC online measurements
Fine carbonaceous aerosol characteristics at a megacity during the Chinese Spring Festival as given by OC/EC online measurements
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OC/EC在线测量给出的春节期间特大城市细小碳质气溶胶特征
DOI：
10.1016/j.atmosres.2016.06.007
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发表时间：
2016-11-15
影响因子：
5.5
通讯作者：
Zhang, YuFen
中科院分区：
文献类型：
--
作者：
Liu, Baoshuang;Bi, Xiaohui;Zhang, YuFen
OC/EC在线监测活动于2015年2月8日至3月15日中国春节期间（CSFP）在中国天津开展。利用相关在线监测仪器，对OC、EC、BC及其他环境污染物（如SO2、NO2、PM2.5等）的高时间分辨率浓度进行测量。 CSFP期间，根据PM2.5浓度峰值和空气动力学直径在0.3～2.5μm之间的气溶胶粒子数浓度（NC），大致识别并展示了5起污染事件。这些污染事件与大型烟花燃放、冬季取暖等燃烧活动以及稳定的气象条件等密切相关。CSFP期间，EC和OC浓度出现了高达1个数量级的变化。仪器本身的不确定性以及测量方法的差异，进一步造成了热OC（热法测得的OC）和光学OC（光学法测得的OC）浓度的差异，以及热EC（热法测得的EC）和光学EC（光学法测得的EC）浓度的差异。高浓度碳质气溶胶会增大测量仪器的不确定度，降低OC和EC之间的相关性，增大热EC、光学BC和光学EC之间的差异。当CSFP期间污染事件形成时，OC/EC比值和SOC/OC百分比会下降。由于热POC和热SOC的来源不同，两者的相关性相对较低（R-2 = 0.39）。在 CSFP 期间，热 POC 优于热 OC。 (C) 2016 Elsevier B.V. 保留所有权利。
The OC/EC online monitoring campaign was carried out in Tianjin of China from 8th February to 15th March 2015 during the Chinese Spring Festival period (CSFP). The concentrations of OC, EC, BC and other ambient pollutants (e.g. SO2, NO2 and PM2.5, etc.) in high time resolution were measured with related online-monitoring instruments. During the CSFP, according to the peaks of PM2.5 concentrations and number concentrations (NC) of aerosol particles with aerodynamic diameters between 0.3 and 2.5 mu m, five pollution-events were generally identified and displayed. These pollution-events were closely associated with large-scale fireworks displaying, combustion activities such as heating for winter, and the stable meteorological conditions, etc. During the CSFP, EC and OC concentrations showed variations up to one order of magnitude. The uncertainty of instrument itself and the difference for measured methods, further caused the differences between thermal OC (measured OC by thermal method) and optical OC (measured OC by optical method) concentrations, as well as between thermal EC (measured EC by thermal method) and optical EC (measured EC by optical method) concentrations. The high concentration carbonaceous aerosols could enlarge the uncertainty of measuring instrument, reducing the correlations between OC and EC, and enhance the differences among thermal EC, optical BC and optical EC. The OC/EC ratios and the percentages of SOC/OC would be declined, when the pollution-events formed during the CSFP. Due to the different sources for thermal POC and thermal SOC, the correlation of the two was relatively lower (R-2 = 0.39). Thermal POC dominated over thermal OC during the CSFP. (C) 2016 Elsevier B.V. All rights reserved.