Spatiotemporal variations of PM_(2.5) and PM_(10) concentrations between31 Chinese cities and their relationships with SO_2,NO_2,CO and O_3

The variations of mass concentrations of PM_(2.5),PM_(10),SO_2,NO_2,CO,and O_3 in 31 Chinese provincial capital cities were analyzed based on data from 286 monitoring sites obtained between March 22,2013 and March 31,2014.By comparing the pollutant concentrations over this length of time,the characteristics of the monthly variations of mass concentrations of air pollutants were determined.We used the Pearson correlation coefficient to establish the relationship between PM_(2.5),PM_(10),and the gas pollutants.The results revealed significant differences in the concentration levels of air pollutants and in the variations between the different cities.The Pearson correlation coefficients between PMs and NO_2 and SO_2 were either high or moderate(PM_(2.5) with NO_2:r=0.256-0.688,mean r=0.498;PM_(10) with NO_2:r = 0.169-0.713,mean r = 0.493;PM2.5 with SO_2:r= 0.232-0.693,mean r=0.449;PM_(10) with SO_2:r = 0.131-0.669,mean r=0.403).The correlation between PMs and CO was diverse(PM_(2.5):r = 0.156-0.721,mean r=0.437;PM_(10):r=0.06-0.67,mean r= 0.380).The correlation between PMs and O_3 was either weak or uncorrelated(PM_(2.5):r--0.35 to 0.089,mean r=-0.164;PM_(10):r=-0.279 to 0.078,mean r=-0.127),except in Haikou(PM2.5:r=0.500;PM_(10):r-0.509).     

Spatiotemporal variations of PM2.5 and PM10 concentrations between31 Chinese cities and their relationships with SO2,NO2,CO and O3

The variations of mass concentrations of PM_2.5,PM₁₀,SO₂,NO₂,CO,and O₃ in 31 Chinese provincial capital cities were analyzed based on data from 286 monitoring sites obtained between March 22,2013 and March 31,2014.By comparing the pollutant concentrations over this length of time,the characteristics of the monthly variations of mass concentrations of air pollutants were determined.We used the Pearson correlation coefficient to establish the relationship between PM_2.5,PM₁₀,and the gas pollutants.The results revealed significant differences in the concentration levels of air pollutants and in the variations between the different cities.The Pearson correlation coefficients between PMs and NO₂ and SO₂ were either high or moderate(PM_2.5 with NO₂:r=0.256-0.688,mean r=0.498;PM₁₀ with NO₂:r = 0.169-0.713,mean r = 0.493;PM2.5 with SO₂:r= 0.232-0.693,mean r=0.449;PM₁₀ with SO₂:r = 0.131-0.669,mean r=0.403).The correlation between PMs and CO was diverse(PM_2.5:r = 0.156-0.721,mean r=0.437;PM₁₀:r=0.06-0.67,mean r= 0.380).The correlation between PMs and O₃ was either weak or uncorrelated(PM_2.5:r--0.35 to 0.089,mean r=-0.164;PM₁₀:r=-0.279 to 0.078,mean r=-0.127),except in Haikou(PM2.5:r=0.500;PM₁₀:r-0.509).