哈尔滨市一次大气污染过程及潜在源分析

本研究以2018年12月10~13日哈尔滨市一次严重的空气污染事件为研究对象，分析了此次污染过程的概况、成因以及污染的潜在源区.结果表明：此次空气污染过程以PM_2.5影响为主，污染类型由10日00：00~11日17：00的偏燃煤型发展为11日17：00~13日15：00的二次气溶胶复合污染，最终在13日15：00后稳定为偏燃煤型.从天气形势和风速风向分析可知此次10~13日的污染过程与不利气象扩散条件也是密不可分的.模拟的48h后向轨迹经过聚类分析主要分为4类，大部分来自内蒙古、吉林等方向，70.83%的轨迹PM_2.5超标，表明来自这些方向的污染气团对哈尔滨市的空气质量影响较大；而通过对模拟的48h后向轨迹进行PSCF、CWT分析，发现哈尔滨的WPSCF和WCWT分布特征类似，WPSCF和WCWT的高值主要集中在哈尔滨本地的双城、巴彦、阿城、吉林省的中部、西部地区等地区，以及大庆、绥化等地区，说明这些区域都是哈尔滨市PM_2.5的潜在源地.

An air pollution process and potential sources of Harbin

A case study was carried out in Harbin during the severe air pollution period from December 10^th to 13^th, 2018, with focuses on the formation, evolution and potential source areas. The results showed that the air pollution process was dominated by PM_2.5. The pollution type was dominated by coal combustion from 00:00 on the 10^th to 17:00 on the 11^th, then developed into the secondary aerosol pollution from 17:00 on the 11^th to 15:00 on the 13^th, and eventually stabilized as being dominated by coal combustion after 15:00 on the 13^th. Based on the analysis of weather situation, wind speed and wind direction, it can be seen that the pollution process was inseparable from the unfavorable diffusion conditions. The simulated 48h backward trajectories were mainly divided into 4categories after clustering analysis, most of them came from Inner Mongolia, Jilin and other directions. PM_2.5 exceeded the air quality standard for 70.83% of the trajectories, indicating the polluted air mass from these directions had a greater impact on the air quality of Harbin. Through the PSCF and CWT analysis of the simulated 48h backward trajectory, it was found that the WPSCF and WCWT distribution characteristics in Harbin were similar. The high values of WPSCF and WCWT were mainly concentrated in Harbin's Shuangcheng, Bayan, Acheng, Jilin Province's central and western regions, as well as Daqing and Suihua, indicating that these areas were the potential source areas of PM_2.5 in Harbin.