天津城区大气气溶胶质量浓度分布特征与影响因素

根据中国气象局天津大气边界层观测站2009年的气溶胶观测资料和同期气象资料,对天津城区PM10和PM2.5质量浓度变化特征,及其与气象条件的相互关系进行研究,结果表明：PM10和PM2.5年均质量浓度为153.24和68.78μg·m-3,其日均值超标率近半,表明南部城区尤其是交通干道附近气溶胶污染较为严重;PM10和PM2.5质量浓度逐月变化呈现明显的冬季高、夏季低的特征,其日变化特征呈明显的双峰型,早晚污染高峰主要受交通源影响;气象条件对气溶胶质量浓度作用显著,气溶胶质量浓度与气温正相关,相对湿度的增高易导致细粒子吸湿性增长,但高湿状态下易引起降水有利于气溶胶的湿清除,西南气流和偏北风是PM10和PM2.5高浓度的主要影响风向,静小风易造成气溶胶堆积,高风速可引起PM10排放增多,但对PM2.5影响不大。

Variety characteristics and influence factors of aerosol mass concentrations in Tianjin city

To research on variety characteristics and influence factors of atmospheric aerosol mass concentrations in Tianjin city,the observational data of PM10 and PM2.5 mass concentrations and the main meteorological factors such as temperature,relative humidity,wind speed and wind direction in 2009 were studied.The result indicated that the aerosol pollution was serious in Tianjin city,with the high average PM10 and PM2.5 mass concentrations（153.24 μg·m-3 and 68.78 μg·m-3）.PM10 and PM2.5 mass concentrations had obvious diurnal variation,with two peak values in the morning and evening respectively,which were affected by traffic sources.PM10 and PM2.5 mass concentrations were influenced by diurnal variation of meteorological factors.PM2.5 mass concentration was positively correlated with the temperature and relative humidity,but too high relative humidity often mean rainfall,which led to reduction of the PM10 and PM2.5 mass concentrations.PM10 and PM2.5 mass concentrations were larger when the wind direction was southwest or north.The impact of wind speed on PM10 and PM2.5 was different,more PM10 and less PM2.5 with higher wind speed.As to the meteorological factors,PM2.5 high mass concentrations correlated well with the high temperatures,low wind speed and determinate relative humidity.