Simulation Analysis Of Black Carbon Aerosol Variation Characteristics In Shijiazhuang City

In this paper,the BC-1054 was used to continuously monitor the BC concentration in Shijiazhuang for 2 years,to study its temporal change characteristics,influencing factors and simulate its spatial distribution,and finally analyze its pollution source.The results showed that the average daily concentration of BC from 2018.08 to 2020.08 was 3.36μg·m^-3,and it showed a"double peak and single valley"trend within 24 h,the peak occurred in the morning and evening peak;The difference was significant and the average was decreased by years.The seasonal phenomenon was"high in winter and low in summer".The concentration gradually decreases to both ends with January as the center,which coincides with the end of the year and the heating season,the BC concentration emitted by artificial activity was high,and the temperature inversion was frequent in winter,the atmospheric structure was relatively stable,which is harmful to the diffusion of pollutants near the ground.Therefore,the BC concentration was high;the BC background concentration at this point was 1.75μg·m^-3,which is at the upper-middle level in the country,5.87 times that of the Wariguanshan station,indicated that the BC pollution at this point cannot be underestimated.Based on the correlation analysis of the atmospheric environmental factor of national control points,found that it was highly correlated with PM_2.5,PM₁₀,CO and NO₂,the obtained equation was applied to he distribution simulation of BC concentration at state controlling found that the average concentration was 3.47μg·m^-3,and the BC concentration at each site decreased with the increase of the year.The average improvement rate reached 19.74%.Due to the impact of vehicle exhaust and industrial enterprise emissions,the BC concentration at the Xinangaojiao and Gaoxinqu showed a continuously high value.The HYSPLIT found that the air masses all originate in the northwest,and the Siberian cold high pressure was affected in the autumn and winter,External source will lead to high BC.Finally,according to WPSCF results,the potential source of BC in Shijiazhuang is mainly concentrated in the north-central Shanxi Province and the southwestern Hebei Province.The results of this study can provide a scientific basis and reference value for further research on BC and urban environment construction.