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／m^3，标准差是±193．7μg／m^3．在50～100μg／m^3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／m^3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／m^3，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／m^3，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．
Continuous observation of PM2.5 was conducted in Taiyuan during high pollution seasons from 17 December 2005 to 28 March 2006. PM2.5 samples were collected using TEOM series 1400a ambient particulate monitor （Rupprecht ＆ Patashnick Co., Inc, USA）. The study showed that the concentrations of PM2.5 were high during winter and spring in Taiyuan. The average hourly mass concentration of PM2.5 was （247.6 ± 193.7）μg/m^3 , which showed fine particles pollution was serious in Taiyuan. The frequency of hourly averages PM2.5 concentrations less than 400μg/m^3 is 84.1%. The PM2.5 concentration has an obvious diurnal variation. The meteorological conditions have significant effects on the ambient concentrations of PM2.5 . The wind speed, relative humidity, and atmospheric pressure were major factors that influence the concentration variation of PM2.5. The 3 d air mass backward trajectories were calculated and clustered to analyze transport pathways of the air pollution in Taiyuan. The 3^td cluster trajectory, which moving paths was from the southwest of Taiyuan, had higher average PM2.5 concentration （342.6μg/m^3 ） than other clusters （ e.g. 261.1 μg/m^3 from east, 225.6μg/m^3 from northwest）. The concentrations of PM2.5 on sandstorm weather are analyzed.
出处
《中国科学院研究生院学报》
CAS
CSCD
2007年第5期648-656,共9页
Journal of the Graduate School of the Chinese Academy of Sciences
基金
山西省气象局开放式研究基金项目(SX054001)资助
关键词
PM2.5
质量浓度
气象条件
后向轨迹
PM2.5 , mass concentration, meteorological conditions, backward trajectories
