2013-2021年山东大气污染特征及气象条件分析OACSTPCD

The hourly data from environmental monitoring stations in Shandong province during 2013-2021 was used to characterize six pollutants,to explore the temporal and spatial distributions of particulate matter(PM)and ozone(O3),and to analyze the meteorological conditions and sources of pollution.The results show that the air quality in Shandong province has improved year by year from 2013 to 2021.The annual mean mass concentration of PM2.5 in 2021 decreased by 60.2%compared to that in 2013.The annual mean concentration of O3 shows a ris-ing trend year by year during 2013-2021,while the concentrations of the other five pollutants decrease.PM and O3 are the most important pollutants affecting the air quality in Shandong province.CO,NO2,PM10,PM2.5,and SO2 concentrations exhibit a unimodal pattern characterized by highs in winter and lows in summer;O3 concentrations show a unimodal pattern feature with the highest in summer and the lowest in winter.The spatial distribution is characterized by high pollutant concentrations in the central and western part of Shandong province and low con-centrations in the eastern part of Shandong province.Environmental meteorological index and atmospheric self-pur-ification capacity index characteristics show that the combination of favorable meteorological conditions and emis-sion reduction during 2013-2021 led to a 59 μg·m-3 decrease in the annual average concentration of PM2.5 in 2021 compared to that in 2013,with emission reduction as the main reason.Source apportionment shows that the propor-tion of PM2.5 from local emissions is high in most areas of Shandong province.The share of local emissions de-creased in 2021 compared to that in 2019.An area is closer to Hebei and He'nan provinces,the share of exogenous transmission is the larger.Local emissions in the seven corridor cities accounted for 31%～54%in 2019,and 19%～34%in 2021,with northwest Shandong province being the most affected by external transport.