Lei Yu, Zhang Xiao-Ling, Kang Ping, Wang Hao-Lin, Qing Quan, Ou Yi-Han, Lu Ning-Sheng, Deng Zhong-Ci
Plateau Atmosphere and Environment Key Laboratory of Sichuan Province, School of Atmospheric Sciences, Chengdu University of Information Technology, Chengdu 610225, China.
School of Atmospheric Sciences, Sun Yat-sen University, Guangzhou 510275, China.
Huan Jing Ke Xue. 2020 Jul 8;41(7):3021-3030. doi: 10.13227/j.hjkx.201911096.
Atmospheric particulate matter pollution in Zigong City in southern Sichuan is quite severe. The average concentrations of PM and PM from 2015 to 2018 were (95.42±9.53) μg·m and (65.95±6.98) μg·m, with an obvious trend of decline. The concentrations of PM and PM in winter were much higher than in other seasons, with the highest average concentrations being(138.08±52.29) μg·m and (108.50±18.05) μg·m in January, respectively, whereas in summer, the average concentrations were lowest. The average ratio of PM to PM is 69.12%, and the ratio in winter is about 1.17 times that in summer; thus, PM is mainly responsible for the air pollution. To explore the potential sources of fine particulate matter (PM) in Zigong City and the pollution contributions of different sources in different seasons, the concentration of PM in Zigong and the daily trajectory after 72 h were calculated and clustered by the combined use of a variety of potential source analysis methods and data. These methods and data included the hybrid single particle lagrangian integrated trajectory (HYSPLIT) model, global data assimilation system (GDAS) meteorological data, potential source contribution analysis (PSCF), and concentration of weight trajectory analysis (CWT). The results showed that the area near Zigong is mostly controlled by southeasterly, westerly, and northwesterly winds in all seasons, and the high PM concentration is mostly located in the low-wind-speed zone of 0-2 m·s. The influence of different seasons and transport routes on PM pollution in Zigong is significant. In spring, it is mainly affected by short-distance air flow from the west and north; in summer, the pollution mainly comes from the southeast air flow of short-distance transportation; in autumn, it is mainly affected by short-distance transportation air flow from Ziyang, Suining, Chongqing, and Neijiang; and in winter, it is not only affected by the surrounding cities such as Ziyang, Suining, and Neijiang but also by the long-distance transportation air flow from central Tibet. In general, the potential source area of particulate matter in Zigong City is mainly located in the border area between the west of Chongqing and the south of Sichuan. In winter, the main contribution area is at its widest, while in summer, the potential source area is smallest.
四川南部自贡市的大气颗粒物污染相当严重。2015年至2018年，PM 和PM 的平均浓度分别为(95.42±9.53) μg·m 和(65.95±6.98) μg·m，呈明显下降趋势。冬季PM 和PM 的浓度远高于其他季节，1月份平均浓度最高，分别为(138.08±52.29) μg·m 和(108.50±18.05) μg·m，而夏季平均浓度最低。PM 与PM 的平均比值为69.12%，冬季该比值约为夏季的1.17倍；因此，PM 是造成空气污染的主要原因。为探究自贡市细颗粒物(PM )的潜在来源以及不同季节不同来源的污染贡献，综合运用多种潜在源分析方法和数据，计算并聚类了自贡市PM 的浓度及72小时后的日轨迹。这些方法和数据包括混合单粒子拉格朗日积分轨迹(HYSPLIT)模型、全球数据同化系统(GDAS)气象数据、潜在源贡献分析(PSCF)以及浓度权重轨迹分析(CWT)。结果表明，自贡市附近区域四季大多受东南风、西风和西北风控制，高PM 浓度大多位于0 - 2 m·s的低风速区。不同季节和传输路径对自贡市PM 污染的影响显著。春季主要受来自西部和北部的短距离气流影响；夏季污染主要来自短距离输送的东南气流；秋季主要受来自资阳、遂宁、重庆和内江的短距离输送气流影响；冬季不仅受资阳、遂宁和内江等周边城市影响，还受来自西藏中部的长距离输送气流影响。总体而言，自贡市颗粒物的潜在源区主要位于重庆西部与四川南部的交界区域。冬季主要贡献区域最广，夏季潜在源区最小。
