| Aerosol is an important component of the atmospheric,as a fine particles in the air,it is bad forhuman health,at the same time,it has some influences directly or indirectly in atmospheric precipitation and chemical reactionsin air,as well as regional climate,global warming effect,so it has attracted widespread attention in atmospheric chemistry and physics of clouds and precipitation,climatology.Black carbon aerosol,as a black carbon particle suspended in air,occupies a large proportion in atmospheric aerosols.It absorbs solar radiation,affects atmospheric circulation,and promotes global water cycle,which directly affects regional air quality.Because of its unique role in the atmosphere,it has become a major concern in the field of atmospheric science.Through the study of black carbon aerosol city,to understand the spatial and temporal distribution of concentration changes,reveal the relationship with meteorological elements in Wuhan City,help the analysis of atmospheric environment quality,the source and the transport of path and characteristics of black carbon,it also plays an important role in the balance of radiation,the changes of local climate and air quality of the environment and human health.This article selects 10 sampling pointsin downtown area of Wuhan to observe black carbon aerosol by using AE-51 black carbon instrument collection in July 2015 to June 2016 and collect meteorological data and pollutant data over the same period.The correlation analysis,linear regression and other methods of mathematical statistics and HYSPLIT trajectory model-4 are used to sort of black carbon aerosol concentration data of time and space analysis,modeling analysis and the trajectory simulation and the analysis of the source,in order to fully understand the characteristics of black carbon aerosol concentration distribution in Wuhan city,discussion the homology with the main pollutants,At the same time,the main source,transmission characteristic and mode are summarized,and a series of environmental management measures and Suggestions are put forward.The main conclusions of this paper include:(1)From July 2015 to June 2016,the black carbon aerosol mass concentration in Wuhan city is on average(3911 ± 2095)ng·m-3,in the range from 1135 to 10742 ng·m-3,the 81%of data have a range from 2000 to 6000 ng·m-3;the year in Wuhan city BC concentration has obvious regularity of monthly mean,showed a single peak distribution,Ranking of BC month average concentration,the size of the relationshipwasJanuary>December>February>October>March>May>November>April>September>August>June>July,which in January was the highest quality and the lowest in July.In the season distribution,it had a trend of in winter>spring>summer>autumn.At the same time,compared with the cities at home and abroad,the background concentration of black carbon aerosol in Wuhan was at the middle level.(2)Black carbon has positive correlated with PM2.5,PM10,CO,SO2,NO2,and has a moderate negative correlation with O3,the correlation coefficients are 0.863,0.657,0.647,0.518,0.466,-0.366.The sources of black carbon aerosol of downtown area of Wuhan come from fuel combustion sources and vehicle emissions as the representative of the flow single source.The modeling analysis of black carbon and PM2.5,PM10,CO find that three order curve function is best fit.Using multiple linear regression analysis,the regression equation can be established with black carbon and PM2.5,PM10,SO2:Y=1493.322+43.623X1-24.505 X2+40.12X3.(3)At 0.01 level,black carbon has a significant correlation with temperature,visibility and pressure,and the correlation coefficients are-0.626,-0.529,and 0.523.The linear regression equation of black carbon and wind speed,temperature,visibility and pressure is Y=7744.17-143.87X1-330.38X2+546.613X3.When the temperature is high and the air pressure is low,the air convection motion is obvious,and it is easy to form precipitation.The wet deposition of black carbon increased,resulting in the low concentration of black carbon in the air.(4)Typical black carbon pollution incidents in Wuhan City are mainly affected by the trajectory of air masses from the north.Through Henan and Hebei provinces,pollutants are easily transported to Wuhan City under control.Trajectory clustering and the calculation results show that the concentration of winter track black carbon average concentration is highest in a year and the lowest in summer.By around the source has great influence in spring and autumn,and winter and summer is mainly from local sources.The results of PSCF analysis show that the areas with PSCF above 0.6 are mainly concentrated in the eastern part of Hunan,northwest Jiangxi,central Henan and Anhui,which are potential sources of black carbon aerosols in Wuhan.(5)In view of the spatial and temporal distribution,pollution characteristics and source analysis of black carbon aerosol in Wuhan,some Suggestions on atmospheric environmental management are put forward:the implementation of regional atmospheric environment pollution partition management system;strengthen the central region of the joint prevention and control of regional cooperation;reducing the pollutant emissions,strengthening the monitoring capacity of PMio,CO,SO2 and other pollutants,improving the supporting measures;implementing the Wuhan blue sky action plan,and actively carry out pollution investigations in the air supervision and key industries;strengthening environmental publicity and education to raise people's awareness of environmental protection. |
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