【摘要】 采用美国R&P公司生产的TEOM系列1400a大气粒子(PM2.5)监测仪于2005年12月17日至2006年3月28日对太原地区PM2.5质量浓度进行在线观测.对观测期间2417个PM2.5小时平均质量浓度观测数据进行分析,得到小时平均质量浓度的平均值是247.6μg/m3,标准差是±193.7μg/m3.在50~100μg/m3之间的PM2.5质量浓度出现的频率最高,PM2.5小时平均质量浓度小于400μg/m3出现的频率为84.1%.PM2.5质量浓度日变化为双峰双谷型.太原市区PM2.5质量浓度与风速、能见度和气压呈负相关,与相对湿度呈正相关.通过3d后向轨迹分析了影响太原地区气团的主要传输路径,结果表明,100m高度上空的后向轨迹可划分为7种基本类型,其中第3类轨迹对应的PM2.5质量浓度值为342.6μg/m3,明显高于其他类型.这类轨迹主要是来自太原的西南方向;而来自东边方向的第1类轨迹对应的PM2.5质量浓度为261.1μg/m3,也比来自西北方向的2、4类轨迹PM2.5质量浓度高.观测结果表明,在沙尘暴影响严重的日期,太原地区PM2.5质量浓度会极大地增加,从而对大气环境形成严重的污染.更多还原

【Abstract】 Continuous observation of PM_2.5 was conducted in Taiyuan during high pollution seasons from 17 December 2005 to 28 March 2006.PM_2.5 samples were collected using TEOM series 1400a ambient particulate monitor（Rupprecht & Patashnick Co.,Inc,USA）.The study showed that the concentrations of PM_2.5 were high during winter and spring in Taiyuan.The average hourly mass concentration of PM_2.5 was（247.6±193.7）μg/m³,which showed fine particles pollution was serious in Taiyuan.The frequency of hourly averages PM_2.5 concentrations less than 400μg/m³ is 84.1%.The PM_2.5 concentration has an obvious diurnal variation.The meteorological conditions have significant effects on the ambient concentrations of PM_2.5. The wind speed,relative humidity,and atmospheric pressure were major factors that influence the concentration variation of PM_2.5.The 3 d air mass backward trajectories were calculated and clustered to analyze transport pathways of the air pollution in Taiyuan.The 3^rd cluster trajectory,which moving paths was from the southwest of Taiyuan,had higher average PM_2.5 concentration（342.6μg/m³）than other clusters（e.g.261.1μg/m³ from east,225.6μg/m³ from northwest）.The concentrations of PM_2.5 on sandstorm weather are analyzed.更多还原