天津冬季大气能见度与空气污染的相互关系

为探求天津冬季大气能见度特征与空气污染的相互关系,于2008年12月至2009年1月连续观测大气能见度和空气污染物浓度(PM10、PM2.5质量浓度,O_3、NO_2和SO_2体积浓度),并结合相对湿度进行相关分析。结果表明:天津冬季大气能见度平均值为11.59 km,日变化呈明显的单峰特征,其变化特征受到空气污染物,尤其是气溶胶质量浓度及相对湿度变化共同影响;观测期内霾的发生频率接近50%;采用非线性回归方程拟合能见度与气溶胶质量浓度相互关系显示,PM2.5质量浓度对水平能见度的贡献大于PM10质量浓度,并且高湿情况下,能见度与气溶胶质量浓度相关性更好。

Correlation of Horizontal Visibility and Air Pollution Concentration in Winter in Tianjin

To understand the characteristics of horizontal visibility and correlation with air pollution in winter in Tianjin,the observational data of PM10 and PM2.5 mass concentrations,reactive gas bulk concentrations,and horizontal visibility in December of 2008 and January of 2009 are studied.The results indicate that the average horizontal visibility value was 11.59 km,and the diurnal variation exhibited a single-peak pattern with the maximum in the afternoon,which were affected strongly by aerosol mass concentrations and relative humidity.The occurrence frequency of haze approached 50%,which,being an important symbol of the poor air quality,resulted in low horizontal visibility.The observational data of PM10 and PM2.5 mass concentrations can be used to reflect the horizontal visibility approximately by using different nonlinear regression equations in winter.There was a negative correlation between horizontal visibility and aerosol mass concentration,and PM2.5 has greater effect on visibility than PM10 does.Under the high humidity condition,there existed better correlation between visibility and aerosol mass concentration.