辽宁本溪大气颗粒物浓度特征

Atmospheric particle concentration characteristics in Benxi,Liaoning

利用本溪大气成分监测站2008年3月至2009年2月大气颗粒物监测仪GRIMM180的连续监测资料,对该地区大气颗粒物的质量浓度变化、谱分布特征以及大气颗粒物与气象因素的关系进行分析研究.结果表明,本溪PM10和PM2.5平均质量浓度分别为0.086 mg.m-3和0.058 mg.m-3,其日平均质量浓度变化幅度较大;冬季和夏季质量浓度日变化均呈现明显的双峰双谷特征;数浓度谱分布较好地符合Junge分布;PM10日平均值超标率为8.7%,且大气颗粒物主要是以细粒子的形式存在;随风速的增大大气颗粒物质量浓度基本呈现逐渐减小的趋势,当风速>0.6 m.s-1时,大气颗粒物质量浓度随风速增大下降明显,风速>3.0 m.s-1时,下降的趋势减缓;降水过程对大气颗粒物有清除作用,其中对粗粒子的清除效果非常明显.

The variations of atmospheric particle mass concentration,size distribution and their relationships with weather conditions have been studied using the data during the period from March 2008 to February 2009 obtained at the air component monitoring station of Benxi.The results show that the mean mass concentration of PM10 and PM2.5 are respectively 0.086 mg · m-3 and 0.058 mg · m-3,and their daily average concentrations have a large variation range.Daily variation of mass concentration was characterized by a clear double-peak and double bottom pattern in winter and summer.The particle size distribution agrees well with Junge distribution.About 8.7% PM10 daily average concentrations exceeded the National Air Quality Standard,and atmospheric particles exist mainly in the form of fine particles.When the wind speed was higher than 0.6 m · s-1,there was an obvious dilution effect on particle mass concentration.And when higher than 3.0 m · s-1,the relevance is not highly apparent.Precipitation had a scavenging effect on atmospheric particles and the scavenging effect is more apparent to the coarse particles.