中国北方气溶胶散射和PM_(10)浓度特征

Characteristics of Aerosol Light-Scattering and PM_(10) Concentration in North China

利用积分浊度计和PM10浓度监测仪,对中国北方2005年观测的气溶胶散射系数σsp与可吸入颗粒物PM10质量浓度的分析表明,张北站σsp年均值为130 Mm-1,民勤站σsp年均值为116 Mm-1;四季中都是冬季均值最高,张北站sσp为301.6 Mm-1,民勤站σsp为170.9 Mm-1,这说明张北站的气溶胶散射情况比民勤站显著。而PM10浓度反映了不同的变化规律,张北站PM10年均值为53μg.m-3,民勤站PM10年均值为130μg.m-3;四季中都是春季均值最高,张北站PM10为82.2μg.m-3,民勤站PM10为190.1μg.m-3,这说明民勤站的PM10污染比张北站严重很多。张北站的质量散射效率α年均值为2.4 m2.g-1,民勤站的α年均值为1.1 m2.g-1,这与张北站全年主要受城市污染型气溶胶的影响,而民勤站全年主要受沙尘气溶胶的影响有密切关系。α具有反映中国北方两种典型气溶胶的能力。

Aerosol light-scattering coefficient at 525 nm （σsp） and PM10 concentration were investigated at two meterological stations of North China in 2005. ospat Minqin in Gansu Province had a mean value of 130 Mm^-1 , while at Zhangbei station in Hebei Province this value was 116 Mm^-1. The highest seasonal mean σspwas encountered in winter at both the stations. Mean σsp at Zhangbei and Minqin stations in winter were 301.6 Mm^-1 and 170.9 Mm^-1 , repectively. Aerosol light-scattering at Zhangbei station was more significant than at Minqin station. Conversely, PM10 at Zhangbei station had a mean value of 53 μg·m^-3, while at Minqin station this value was 130 μg·m^-3. The largest seasonal mean PM10 was encountered in spring at both the stations. The mean PM10 at Zhangbei and Minqin stations in spring were 82.2 μg·m^-3 and 190.1 μg·m^-3 , repectively. PM10 pollultion at Minqin station was more significant than at Zhangbei station. As to the characteristics of mass scattering efficiency （α）, α at Zhangbei station had a mean value of 2.4 m^2·g^-1, while at Minqin station this value was 1.1 m^2·g^-1. Obviously, the characteristics of aerosol properties at two stations were different, which resulted from different types of aerosol dominated at two stations. Zhangbei station is mainly affected by urban polluted aerosol due to its energy stucture and its location near urban polluted belt in East China, however Minqin station is mainly affected by desert aerosol due to its location near two big deserts in North China.