摘要
南极地区提供了地球上最好的研究气溶胶的背景组成场所,为此,我们用八级阶式撞击采样器采集了不同粒径的样品。采样于1986年间在南极中国长城站进行,样品分析方法是质子激发X射线发射法(PIXE)。为了研究不同元素的富集因子,将全部结果分为两组,粒径大于10/μm粒子为粗粒,小于10/μm的粒子为细粒,并且还讨论了粗、细粒中各元素的相关因子,长城站气溶胶所测元素结果与其他地区采样点所测结果作了比较,证明南极地区是地球上良好的背景地区。
Atmospheric pollution is not only directly harmful to human health at source region but it also be transported through the atmosphere over great distances. Atmospheric particles, especially submicron aerosol particles which have long atmospheric residence times have led to the contamination of many non-urban areas. Baseline atmosphericumcasure-ments should help us make clear the source, dispersion, concentrations, degree of transportation and enrichment factors of these pollutants. The Antarctica area offers one of the best locations on the Earth for studing the composition of the background aerosol since it is isolated both geographically and meteorologically from the major souices of anthropo-gentric emission.
The aerosol samples were collected by cascade impactors designed and constructed by our Res. Center. Each sample provided eight particle size fractions in the normal aerody
namic diameters (μm) ranges. From first stage to the 7th stage Mylar film in 3μm thickness
was used, Nuclepore film with 0.40μm of pore diameter was used in the last stage. The
samples were collected at flow of two liters per minute. The samples were analysed by Proton Induced X-ray Emission (PIXE) method. The X-ray spectra were analysed by computer, with small peaks being checked by manual integration to obtained the final con
centrations. The data are given in μg per standard cubic meter.
In order to learn the enrichment factors of various elements the results were separated
to two groups: coarse and fine particles. Coarse mode (>10μm) concentrations were
compared with the composition of the earth's crust. The fine mode of elements show large relative enrichments. Authors have compared to those recently measured results at some other locations. It was also showed the aerosol results measured in Antarctica by a part of authors.
It can be concluded that the Antarctica is a good background area on the Earth. The measurements of atmospheric chemical composition, are valuable in order to establish concentration baselines with which polluted air may be compared. They also give an opportunity to investigate the physical and chemical characteristics of the atmosphere withont complicating anthropological influences.
出处
《南极研究》
CSCD
1990年第2期36-43,共8页
关键词
气溶胶
PIXE
南极
长城站
PIXE, aerosol, Grcal Wall Station, Antarctica
