Wang Lu, Yuan Liang, Zhang Xiao-Ling, Jia Yue-Tao
Plateau Atmosphere and Environment Key Laboratory of Sichuan Province, School of Atmospheric Sciences, Chengdu University of Information Technology, Chengdu 610225, China.
Jinxi Meteorological Bureau, Fuzhou 344800, China.
Huan Jing Ke Xue. 2020 Apr 8;41(4):1561-1572. doi: 10.13227/j.hjkx.201908190.
Black carbon (BC) was measured at Chengdu from December 1, 2017, to November 30, 2018, using a seven-channel aethalometer (AE-33). The variation characteristics of BC were obtained. BC sources were explored based on the aethalometer model and a hybrid single particle Lagrangian integrated trajectory model (Hysplit-4). The results showed the BC concentration was the highest in the winter (8.18 μg·m) with the monthly mean of 11.11 μg·m peaking in December, followed by the spring (5.11 μg·m) and autumn (3.91 μg·m), and was the lowest in summer (3.28 μg·m) with the lowest monthly mean of 2.30 μg·m in July. The annual average concentration of BC was 5.26 μg·m with a standard deviation of 4.27 μg·m. The diurnal variations of BC showed typical bimodal patterns in four seasons mainly due to the influence of the boundary layer and traffic rush. The source apportionment of BC showed that the liquid fuel (e.g., vehicle emission) had higher contribution to total BC concentration during all seasons (ranging from 69% in winter to 82% in summer) than solid fuel (e.g., coal and biomass combustion). The contribution of liquid fuel to the total BC was higher in summer, while solid fuel had a higher contribution in winter. The diurnal cycles of BC source apportionment demonstrated that the contribution of liquid fuel increased in the rush hours. The results of potential source contribution function and concentration weighted trajectory showed that the potential sources of BC in Chengdu were slightly different in different seasons and were mainly affected by the different air mass sources. However, the main potential source regions were the surrounding areas of Chengdu and the areas between Chengdu and Chongqing (the Chuanyu City group). The mass contribution to the BC in Chengdu was high in the region where liquid fuel most affected the total BC. Additionally, the southern part of Shaanxi and the southern part of Gansu were also potential sources of BC, and in Summer, some regions in Guangxi and Guizhou could become the source regions of BC in Chengdu.
2017年12月1日至2018年11月30日期间，在成都使用七通道黑碳仪（AE - 33）对黑碳（BC）进行了测量，并得出了BC的变化特征。基于黑碳仪模型和混合单粒子拉格朗日积分轨迹模型（Hysplit - 4）对BC来源进行了探究。结果表明，BC浓度在冬季最高（8.18μg·m³），12月的月均值最高，为11.11μg·m³，其次是春季（5.11μg·m³）和秋季（3.91μg·m³），夏季最低（3.28μg·m³），7月的月均值最低，为2.30μg·m³。BC的年平均浓度为5.26μg·m³，标准差为4.27μg·m³。BC的日变化在四个季节呈现典型的双峰模式，主要受边界层和交通高峰的影响。BC的源解析表明，液体燃料（如车辆排放）在所有季节对总BC浓度的贡献（冬季为69%，夏季为82%）均高于固体燃料（如煤炭和生物质燃烧）。液体燃料对总BC的贡献在夏季较高，而固体燃料在冬季贡献较高。BC源解析的日循环表明，液体燃料的贡献在高峰时段增加。潜在源贡献函数和浓度加权轨迹的结果表明，成都BC的潜在源在不同季节略有不同，主要受不同气团来源的影响。然而，主要潜在源区是成都周边地区以及成都和重庆之间的区域（川渝城市群）。在液体燃料对总BC影响最大的区域，对成都BC的质量贡献较高。此外，陕西南部和甘肃南部也是BC的潜在源，夏季，广西和贵州的一些地区可能成为成都BC的源区。
