Simulation of brownish haze in urban areas of Nanjing

Considering the main chemical components in Nanjing haze,the visibility distribution and hazy phenomena are simulated based on the relationship between haze and visibility.The results show that:the average mass ratio of SO2-4/NO-3 is 5.39;wind speed、relative humidity、and PM2.5 are the main factors of haze;the visibility simulation results are in agreement with the distribution characteristics of all the major components of PM2.5.Sulfate and organic aerosol contribute most to the decrease of visibility in Nanjing,followed by black carbon.