常州城区秋冬季黑炭气溶胶的浓度变化特征

The Concentration Variation Characteristics of Black Carbon Aerosols in Changzhou in Autumn and Winter

根据常州市2012年9月-2013年1月的黑炭气溶胶（Black Carbon，以下简称BC）在线监测数据及常规气象资料，分析了BC在秋冬季不同时间段的变化特征及气象要素对BC的影响。结果表明，常州秋冬季BC平均值为5．17（1．48～17．02）μg／m^3，主要集中在1．00斗μg／m^3～7．50μg／m^3，冬季较高于秋季，小时均值最大值达33．87μg／m^3；BC本底值为3．50μg／m^3；1月份BC日均值变化幅度最大，发生高污染的频率最高。Bc的日变化具有明显的双峰结构，一天中最大浓度多出现在上午06：00-09：00，特殊天气条件下，BC小时值存在不同的分布情况；BC在不同风向的输送条件下有明显的不同，偏东北方向过来的气团易造成BC高污染。

In order to study the pollution characteristics of the black carbon aerosol（BC） in autumn and winter in Changzhou, the variation characteristics of BC on different time scales and the effects of meteorological factors on the BC mass concentration were analyzed based on BC online monitoring data and the regular meteoro- logical data in Changzhou from September 2012 to January 2013. The results showed that the average BC concen- tration during autumn and winter in Changzhou was 5.17 μg/m^3 , with the range 1.48 i＆g/m3 - 17.02 μg/m^3. BC mass concentration was concentrated around the range 1.00 μg/m^3 - 7.50μg/m^3 , with maximum hourly av- erage concentration of 33.87 μg/m^3. In addition, the concentration of BC in winter was higher than that in au- tumn and the base BC mass concentration of this study area was about 3.50 μg/m^3 based on the maximum fre- quency of hourly mean concentration. The biggest variation tendency of daily average BC mass concentration oc- curred in January, which was also the time of high pollution occurred frequently. The daily variation of BC mass concentration was characterized by a pronounced double peak pattern, and the highest value occurred more dur- ing 06：00--09：00 in a day. There can be different distribution of BC hourly mass concentration under special weather conditions. Different characteristics of BC mass concentration were observed for different wind directions that the air mass move from the northeast easy to result in high BC pollution.