Study On Black Carbon Mass Size Distribution In The Rural Background Of North China Plain

Black carbon has always been a hot topic in atmospheric research due to its strong light absorption and significant climate and environmental effects.With the economic development in recent years,black carbon emissions have increased in China,attracting increased attention to black carbon monitoring and emission reduction.The North China Plain is a typical pollution area in China with the highest anthropogenic emissions of black carbon.Accurate analysis of the physical and chemical characteristics of atmospheric black carbon aerosols is of great significance for revealing the impact of black carbon on the regional environment and climate.During a field experiment conducted at a background site in the North China Plain in November 2018,a single particle soot photometer was used to observe the atmospheric black carbon aerosol.Based on a self-developed algorithm,the mass size distributions and number size distributions of black carbon core were derived,and the major influencing factors were analyzed.It was found that the mass and number size distributions of the black carbon core differed during different pollution periods,which mainly reflected the changes of dominated emission sources of black carbon.In addition,wind direction and speed were also found to have a certain effect on the concentration and distribution of black carbon.In the case of high wind speed,the black carbon mass concentration is low,but the sources of black carbon may be more diverse,thus black carbon distribution is broader;on the contrary,In the case of high wind speed and high relative humidity,the source of black carbon may be more uniform,the black carbon distribution is thus narrower.