中文摘要：

利用天津大气边界层观测站2011年4月1日-5月10日PM10和PM2.5质量浓度、气溶胶数浓度资料、大气能见度和常规气象观测数据,分析晴日、霾日、降水日和沙尘日等典型天气条件下气溶胶质量浓度和数浓度的分布特征,并考察风和降水对气溶胶质量浓度和数浓度的影响。结果表明：2011年春季天津城区PM10质量浓度平均值为194.42±164.19μg·m^-3,PM2.5质量浓度平均值为57.89±37.02μg·m^-3,PM2.5/PM10为0.35±0.20;不同天气条件下气溶胶质量浓度和数浓度分布特征差异明显,PM2.5质量浓度在霾日和沙尘日较高,PM2.5-10质量浓度沙尘日最高,降水日最低;PN1霾日最高,晴日最低,PN1-2.5和PN2.5-10沙尘日最高,降水日最低;典型天气下后向轨迹有显著不同,来自偏南和偏西风向的气流易造成细粒子污染而形成灰霾天气,晴日以偏北气流为主,偏东气流易导致降雨;降水对清除气溶胶粗粒子和改善大气能见度作用明显,但降雨前后细粒子数浓度变化不大。

英文摘要：

Based on the data of the PM10 and PM2. 5mass concentration,aerosol number concentration,atmospheric horizontal visibility and meteorological data at Tianjin boundary layer station from April 1 to May 10,2011,the distribution characteristics of the aerosol mass concentration and number concentration were analyzed under the typical weather conditions such as sunny days,haze days,precipitation days and dust days. The results showed that the average concentration of PM10 was 194. 42 ± 164. 19μg·m^- 3while the average concentration of PM2. 5was 57. 89 ± 37. 02μg·m^- 3,the value of PM2. 5/ PM10 was 0. 35 ± 0. 20. The distribution characteristics of aerosol mass concentration and number concentration were significantly different under the typical weather conditions.The PM2. 5mass concentration was higher in the haze days and dust days than sunny days and precipitation days;the PM2. 5- 10 mass concentration was the highest in the dust and the lowest in the rain; the PN1 was the highest in the haze days and the lowest in the sunny days; the PN1- 2. 5and PN2. 5- 10 was the highest in the dust days and the lowest in the precipitation days. The clustering analysis of the wind velocity and direction combination to track in the typical weather conditions showed that the air flow from the south and west easily created the fine particles pollution and the formed the gray haze weather,the north air flow mainly occurred in the sunny days and the east air flow easily lead to rainfall. The precipitation could obviously clean up aerosol coarse particles and improve the visibility,but the number concentrations of the fine particles before and after rain changed a little.