广州市PM_2.5和PM_1.0质量浓度变化特征

文章报道了2005年干季和2006年湿季广州市大气细粒子PM2.5和PM1.0质量浓度的实时监测情况。监测结果表明:干季监测点PM2.5日均质量浓度在11.8～164.0μg/m3之间,总平均值为81.7μg/m3;湿季日均质量浓度在19.9～121.2μg/m3之间,总平均值为57.7μg/m3。干季PM1.0日均质量浓度变化范围为14.9～129.1μg/m3,总平均值为59.4μg/m3;湿季日均质量浓度在11.9～86.7μg/m3之间,总平均值为52.9μg/m3。对比发现,PM1.0总平均质量浓度在干、湿季相差很小,且与湿季PM2.5总平均质量浓度也相差不大,显示PM1.0具有相对固定成因来源且基本不受季节变化影响,而且湿季PM2.5的组成主要由PM1.0大气细粒子构成。干季PM2.5和PM1.0质量浓度日变化特征呈明显夜间高、白天低的特点,质量浓度的最大值都出现在晚上21:00左右;湿季由于雨水频繁,没有明显的日变化特征。气象分析表明,干季大气细粒子质量浓度主要受冷空气影响,而湿季主要受降雨影响。

Characteristics of Mass Concentration Variations of PM2.5 and PM1.0 at Guangzhou

Real time mass concentrations of PM2.5 and PM1.0 at Guangzhou were monitored in dry season of 2005 and wet season of 2006.Results showed that daily average concentration of PM2.5 varied from 11.8μg/m3 to 164.0μg/m3 with total mean value of 81.7μg/m3 in dry season while daily average concentration varied from 19.9μg/m3 to 121.2μg/m3 with total mean value of 57.7μg/m3 in wet season.Daily average concentration of PM1.0 varied form 14.9μg/m3 to 129.1μg/m3 with total mean value of 59.4μg/m3 in dry season while daily average concentration varied from 11.9μg/m3 to 86.7μg/m3 with total mean value of 52.9μg/m3 in wet season.Comparison showed that there are stable source for PM1.0 and the source are not affected by seasonal change.Daily variation of both PM2.5 and PM1.0 mass concentration showed a general mode of lower during day time while higher during night time as peak value were appeared around 21:00 at night.Meteorological condition analysis showed that mass concentration was mainly affected by cold air from north China in dry season while by rainfall in wet season.