全国大气背景地区黑碳浓度特征

分析了2015年14个背景站黑碳浓度水平及分布规律,结果表明:我国背景地区黑碳小时浓度均值呈现明显的对数正态分布特征,14个背景站880 nm波长时年均质量浓度为88.7~1 487.6 ng/m~3,小时最大峰值为685.0~13 731.0 ng/m~3,长岛和衡山相对较高;24 h日浓度变化基本呈现"单峰"状,但峰值出现时刻有所不同;工作日和周末的浓度变化趋势基本相似,但浓度高低与所在区域生产生活方式不同而有所差异。初步探讨了风速和风向与浓度污染水平的关系,相对风速而言,风向对黑碳的浓度影响较大,后向轨迹结果也印证了风向的影响。

The Characteristic of Black Carbon Concentration at National Ambient Air Background Stations

The concentration and distribution of black carbon in different time scale at 14 national ambient air background stations in 2015 were analyzed in this paper. The results showed that the hourly average concentration of black carbon at each station was a logarithmic normal distribution. The hourly peak cocentrations ranged from 685.0-13731.0 ng/m³, and the annual average concentrations were between 88.7-1487.6 ng/m³ among the 14 background monitoring stations. The concentration of black carbon at Hengshan station in Hunan province and Changdao station in Shandong province were higher than the other stations. The hourly average concentration changed as a single peak shape during a whole day, but the peak time were different at the 14 stations. The lariation trends of the concentration in working days and weekends were similar, but the concentration level were different at all the 14 stations, relating to the production and life style in each area. The relationship between the black carbon concentration and the wind speed and wind direction in some typical episode was discussed. The research showed that the wind direction influenced the black carbon concentration more obviously than the wind speed, and the backward trajectory study result also proved the influence of the wind direction.