北京地区PM_(10)和PM_(2.5)质量浓度的变化特征

Characteristics of Mass Concentration Variations of PM_(10) and PM_(2.5) in Beijing Area

北京市区2003-01-16—04-30PM10和PM2 5的监测结果表明,虽然ρ(PM10),ρ(PM2 5)的变化幅度较大,但是其变化趋势非常相似。PM10,PM2 5质量浓度的日变化呈双峰特征分布。ρ(PM2 5) ρ(PM10)的平均值为56 6%,说明可吸入颗粒物(PM10)中细粒子(PM2 5)的含量大于粗粒子(PM2 5～10)。

The monitoring results of PM_(10) and PM_(2.5) in Beijing city area from January 16 to April 30,2003 showed that they varied similarly and were well correlated,although they had wide variations in concentration.PM_(10) and PM_(2.5) had a similar diurnal variation with two peaks in the day.The average ratio of PM_(2.5) to PM_(10) was 56.6% for the whole campaign,indicating that PM_(2.5) had a larger part than other size particles in PM_(10).