ZHAO Hui1, ZHENG Youfei1, 2, 3, XU Jingxin3,SUN Jian4

（1.School of Environmental Science and Engineering,Nanjing University of Information Science＆Technology,Nanjing,210044, China;
2.Jiang su Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Nanjing,210044,China;
3.College of Atmospheric Physics and Environment,Nanjing University of Information Science＆Technology,Nanjing,210044,China;
4.Shanghai Minhang District Meteorological Office, Shanghai,201100,China）

Abstract: In present study, changes of air pollutants concentrations in Beijing, Guangzhou and Nanjing Cities were analyzed based on their corresponding daily average concentrations of six air pollutants (PM2.5, PM10, SO2, CO, NO2 and O3) during the period of March 1, 2014 and February 28, 2014. Correlations between these changes and weather conditions were also discussed. Results show that (1) Guangzhou had the best air quality, while the air quality in Beijing was the most serious. There were 98 excellent air quality days and 222 fine air quality days in Guangzhou, accounted for 26.8% and 60.8%, respectively, of the whole year. As compared with Nanjing, Beijing had 55 excellent air quality days, which was higher than 29 days of Nanjing, however, its moderate pollution days, severe pollution days and serious pollution days were 61, 34 and 8, respectively, all higher than 30, 14 and 0 of Nanjing; (2) year average concentrations of PM2.5, PM10, SO2, NO2 and O3 in Beijing were 80.5, 112.9, 16.8, 53.4 and 57.3 μg/m3 respectively, the datawere 45.9, 67.2, 16.6, 45.7 and 47.9 μg/m3 respectively in Guangzhou, and 70.6, 120.1, 21.5, 50.3 and 54.9 μg/m3 respectively in Nanjing. Year average concentrations of CO in Beijing, Guangzhou and Nanjing were 1.2, 1.0 and 0.9 mg/m3, respectively;(3) standard exceeding rates of the daily average concentrations of PM2.5 in Beijing, Guangzhou and Nanjing were 42.7%, 7.9% and 38.4%, respectively; standard exceeding rates of PM10 were 23.0%, 1.6% and 25.2%, respectively and standard exceeding rates of NO2 were 14.0%, 3.8% and 7.1%, respectively. Only the daily average concentration of CO in Beijing exceeded the standard, and its standard exceeding rate was 1.4%. The daily average concentrations of SO2 in the three cities did not exceed the standard; and(4) wind speed has a significant negative correlation with SO2 and NO2 concentrations. Wind speed has little effect on the CO concentration in Guangzhou, while the concentrations of CO in Beijing and Nanjing decrease with increasing wind speed.Concentrations of PM2.5 and PM10 in Nanjing also decrease with increasing wind speed. When wind speed is higher than 4m/s, it could increase the concentration of PM10 in Beijing and the concentration of PM2.5 and PM10 in Guangzhou. In addition, wind direction also has an effect on the transport of air pollutants.

Key words: Air pollution, Mass concentration, Meteorological condition

EARTH AND ENVIRONMENT Vol.44, No.5 Tot No.313, 2016, Page 549-556