Based on the chemical composition data of a regional long-lasting haze event that occurred in the Yangtze River Delta(YRD)region from 17 December 2023 to 8 January 2024,the evolutionary characteristics of the chemical...Based on the chemical composition data of a regional long-lasting haze event that occurred in the Yangtze River Delta(YRD)region from 17 December 2023 to 8 January 2024,the evolutionary characteristics of the chemical components and sources of fine particulate matter(PM2.5)under different pollution levels were comparatively analyzed using PMF(Positive Matrix Factorization)and backward trajectory analysis.SNA(NO_(3)^(-),NH_(4)^(+),SO_(4)^(2-))was found to be the primary chemical component of PM2.5,making up 63.6%(clean days)to 69.7%(heavy pollution)of it.The NO_(3)^(-)concentration was 3.14(clean days)to 6.01(heavy pollution)times higher than that of SO_(4)^(2-).NO_(3)^(-),POC,Fe,Mn,Al concentrations increased,while SOC,EC,crustal elements(Ca,Si)and other water-soluble ions(WSIs)concentrations decreased as the pollution level increased.The contribution of secondary inorganics and biomass-burning emissions and industrial and ship emissions increased significantly as the pollution level increased,which accounted for 40.3%and 36.7%,respectively,in the heavy pollution stage.The contribution of traffic sources decreases gradually with increasing pollution levels,accounting for only 59.1%of the light pollution stage in the heavy pollution stage.PM_(2.5) and its main chemical components showed similar potential source distribution,located in the northwest(Fuyang,Huainan,Nanjing),south(Taizhou,Lishui,Jiande)and north(Taizhou,Yancheng).However,distinct transport routes were observed under the different air quality levels.During the heavy pollution period,the polluted air masses primarily came from the harbor regions,whereas during the light pollution period they were transported from the southeast(Taizhou)and the North China Plain.展开更多
A distinctive kind of organic carbon aerosol that could absorb ultraviolet-visible radiation is called brown carbon(Br C),which has an important positive influence on radiative budget and climate change.In this work,w...A distinctive kind of organic carbon aerosol that could absorb ultraviolet-visible radiation is called brown carbon(Br C),which has an important positive influence on radiative budget and climate change.In this work,we reported the absorption properties and potential source of Br C based on a seven-wavelength aethalometer in the winter of 2018–2019 at an urban site of Sanmenxia in Fenwei Plain in central China.Specifically,the mean value of Br C absorption coefficient was 59.6±36.0 Mm^(-1) at 370 nm and contributed 37.7%to total absorption,which made a significant impact on visibility and regional environment.Absorption coefficients of Br C showed double-peak pattern,and Br C had shown small fluctuations under haze days compared with clean days.As for the sources of Br C,Br C absorption coefficients expressed strong correlations with element carbon aerosols and primary organic carbon aerosols,indicating that most of Br C originated from primary emissions.The linear correlations between trace metal elements(K,As,Fe,Mn,Zn,and Pb)and Br C absorption coefficients further referred that the major sources of Br C were primary emissions,like coal burning,biomass burning,and vehicle emissions.The moderate relationship between Br C absorption coefficients and secondary organic aerosols suggested that secondary production of Br C also played an important role.The 120 hr backward air mass trajectories analysis and concentration-weighted trajectories analysis were also used to investigate potential sources of Br C in and around this area,which inferred most parts of Br C were derived from local emissions.展开更多
Trace metals associated with PM10 aerosols and their variation during day and nighttime as well as during different seasons have been studied for the year 2012. PCA analysis suggested5 PCs,which accounted for 86.8% cu...Trace metals associated with PM10 aerosols and their variation during day and nighttime as well as during different seasons have been studied for the year 2012. PCA analysis suggested5 PCs,which accounted for 86.8% cumulative variance. PC1 accounted for 30% with a significant loading of metals of anthropogenic origin,while PC2 showed 28% variance with the loading of metals of crustal origin. These trace metals showed seasonal distinct day and night time characteristics. The concentrations of Cu,Pb,and Cd were found to be higher during nighttime in all the seasons. Only Fe was observed with significantly higher mean concentrations during daytime of all seasons except monsoon. The highest mean values of Cu,Cd,Zn,and Pb during post-monsoon might be attributed to winds advection over the regions of waste/biomass burning and industrial activities in Punjab and Haryana regions.Furthermore,concentration weighted trajectory analysis suggested that metals of crustal origin were contributed by long-range transport while metals of anthropogenic and industrial activities were contributed by regional/local source regions.展开更多
Hourly PM2.5 concentrations were observed simultaneously at a cities-cluster comprising 10 cities/towns in Hebei province in China from July 1 to 31, 2008. Among the 10 cities/towns, Baoding showed the high- est avera...Hourly PM2.5 concentrations were observed simultaneously at a cities-cluster comprising 10 cities/towns in Hebei province in China from July 1 to 31, 2008. Among the 10 cities/towns, Baoding showed the high- est average concentration level （161.57μg/m3） and Yanjiao exhibited the lowest （99.35 μg/m3 ）. These observed data were also studied using the joint potential source contribution function with 24-h and 72-h backward trajectories, to identify more clearly the local and countrywide-scale long-range transport sources. For the local sources, three important influential areas were found, whereas five important influential areas were defined for long-range transport sources. Spatial characteristics of PM2.5 were determined by multivariate statistical analyses. Soil dust, coal combustion, and vehicle emissions might be the potential contributors in these areas. The results of a hierarchical cluster analysis for back trajectory endpoints and PM2.s concentrations datasets show that the spatial characteristics of PM2.5 in the cities-cluster were influenced not only by local sources, but also by long-range transport sources. Different cities in the cities-cluster obtained different weighted contributions from local or long-range transport sources. Cangzhou, Shijiazhuang, and Baoding are near the source areas in the south of Hebei province, whereas Zhuozhou, Yangfang, Yanjiao, Xianghe, and Langfang are close to the sources areas near Beijing and Tianjin.展开更多
基金supported by the National Key Research and Development Program of China(No.2022YFC3701204)the Natural Science Foundation of Jiangsu Province(No.BK20231300).
文摘Based on the chemical composition data of a regional long-lasting haze event that occurred in the Yangtze River Delta(YRD)region from 17 December 2023 to 8 January 2024,the evolutionary characteristics of the chemical components and sources of fine particulate matter(PM2.5)under different pollution levels were comparatively analyzed using PMF(Positive Matrix Factorization)and backward trajectory analysis.SNA(NO_(3)^(-),NH_(4)^(+),SO_(4)^(2-))was found to be the primary chemical component of PM2.5,making up 63.6%(clean days)to 69.7%(heavy pollution)of it.The NO_(3)^(-)concentration was 3.14(clean days)to 6.01(heavy pollution)times higher than that of SO_(4)^(2-).NO_(3)^(-),POC,Fe,Mn,Al concentrations increased,while SOC,EC,crustal elements(Ca,Si)and other water-soluble ions(WSIs)concentrations decreased as the pollution level increased.The contribution of secondary inorganics and biomass-burning emissions and industrial and ship emissions increased significantly as the pollution level increased,which accounted for 40.3%and 36.7%,respectively,in the heavy pollution stage.The contribution of traffic sources decreases gradually with increasing pollution levels,accounting for only 59.1%of the light pollution stage in the heavy pollution stage.PM_(2.5) and its main chemical components showed similar potential source distribution,located in the northwest(Fuyang,Huainan,Nanjing),south(Taizhou,Lishui,Jiande)and north(Taizhou,Yancheng).However,distinct transport routes were observed under the different air quality levels.During the heavy pollution period,the polluted air masses primarily came from the harbor regions,whereas during the light pollution period they were transported from the southeast(Taizhou)and the North China Plain.
基金supported by The National Key Research and Development Program of China(No.2017YFC0209500)the National Natural Science Foundation of China(Nos.91744204,41822703,and 91844301)National research program for key issues in air pollution control(No.DQGG-0103)。
文摘A distinctive kind of organic carbon aerosol that could absorb ultraviolet-visible radiation is called brown carbon(Br C),which has an important positive influence on radiative budget and climate change.In this work,we reported the absorption properties and potential source of Br C based on a seven-wavelength aethalometer in the winter of 2018–2019 at an urban site of Sanmenxia in Fenwei Plain in central China.Specifically,the mean value of Br C absorption coefficient was 59.6±36.0 Mm^(-1) at 370 nm and contributed 37.7%to total absorption,which made a significant impact on visibility and regional environment.Absorption coefficients of Br C showed double-peak pattern,and Br C had shown small fluctuations under haze days compared with clean days.As for the sources of Br C,Br C absorption coefficients expressed strong correlations with element carbon aerosols and primary organic carbon aerosols,indicating that most of Br C originated from primary emissions.The linear correlations between trace metal elements(K,As,Fe,Mn,Zn,and Pb)and Br C absorption coefficients further referred that the major sources of Br C were primary emissions,like coal burning,biomass burning,and vehicle emissions.The moderate relationship between Br C absorption coefficients and secondary organic aerosols suggested that secondary production of Br C also played an important role.The 120 hr backward air mass trajectories analysis and concentration-weighted trajectories analysis were also used to investigate potential sources of Br C in and around this area,which inferred most parts of Br C were derived from local emissions.
基金Partial financial support from the CSIR network project(PSC 0112)CSIR fellowship to Subhash Chandra,SRF
文摘Trace metals associated with PM10 aerosols and their variation during day and nighttime as well as during different seasons have been studied for the year 2012. PCA analysis suggested5 PCs,which accounted for 86.8% cumulative variance. PC1 accounted for 30% with a significant loading of metals of anthropogenic origin,while PC2 showed 28% variance with the loading of metals of crustal origin. These trace metals showed seasonal distinct day and night time characteristics. The concentrations of Cu,Pb,and Cd were found to be higher during nighttime in all the seasons. Only Fe was observed with significantly higher mean concentrations during daytime of all seasons except monsoon. The highest mean values of Cu,Cd,Zn,and Pb during post-monsoon might be attributed to winds advection over the regions of waste/biomass burning and industrial activities in Punjab and Haryana regions.Furthermore,concentration weighted trajectory analysis suggested that metals of crustal origin were contributed by long-range transport while metals of anthropogenic and industrial activities were contributed by regional/local source regions.
基金supported by the "Strategic Priority Research Program (B)" of the Chinese Academy of Sciences (XDB05030103)the National Natural Science Foundation of China (71103098 and 21207070)the Fundamental Research Funds for the Central Universities and the Combined Laboratory of the Tianjin Meteorological Bureau
文摘Hourly PM2.5 concentrations were observed simultaneously at a cities-cluster comprising 10 cities/towns in Hebei province in China from July 1 to 31, 2008. Among the 10 cities/towns, Baoding showed the high- est average concentration level （161.57μg/m3） and Yanjiao exhibited the lowest （99.35 μg/m3 ）. These observed data were also studied using the joint potential source contribution function with 24-h and 72-h backward trajectories, to identify more clearly the local and countrywide-scale long-range transport sources. For the local sources, three important influential areas were found, whereas five important influential areas were defined for long-range transport sources. Spatial characteristics of PM2.5 were determined by multivariate statistical analyses. Soil dust, coal combustion, and vehicle emissions might be the potential contributors in these areas. The results of a hierarchical cluster analysis for back trajectory endpoints and PM2.s concentrations datasets show that the spatial characteristics of PM2.5 in the cities-cluster were influenced not only by local sources, but also by long-range transport sources. Different cities in the cities-cluster obtained different weighted contributions from local or long-range transport sources. Cangzhou, Shijiazhuang, and Baoding are near the source areas in the south of Hebei province, whereas Zhuozhou, Yangfang, Yanjiao, Xianghe, and Langfang are close to the sources areas near Beijing and Tianjin.
