北京地区夏季背景气溶胶的特征

本文通过对观测资料的统计分析和比较研究,初步揭示了北京地区夏季背景气溶胶的一些特征,其中包括元素浓度及其变化、富集因子和气溶胶来源等。

CHARACTERIZATION OF THE REGIONAL SUMMER BACKGROUND AEROSOL OF BEIJING, CHINA

Aerosol samples were collected both in urban area of Beijing (BJ) and at Gubeikou(GBK) where the Shangdianzi regional station has been located. More than thirty elements were analyzed by INAA and XRF. There were significant differences between aerosol at BJ and aerosol at GBK. Mass concentrations of TSP and elements of aerosol at GBK were about one magnitude smaller than that at BJ. 1Jnrichment factor (EF) was calculated for each element. Fe was chosen as reference element. Very large }F values for S, As, Se, Sb, I, etc were found both at BJ and at GBK. It suggests that these elements should be mainly derived from anthropogenic sources. Cluster analyses were done according to both correlation coefficients and Euclidean distances among samples. Results showed that aerosol at BJ and aerosol at GBK were not in same cluster in most cases. Principal factor analyses for both GBK aerosol and BJ aerosol were also performed. Four main sources were found for both sites. For GBK aerosol the first important source was coal combustion, the second was soil, the third was probably exhaust of diesel egine and the fourth was refuse. For BJ aerosol, the first and second important sources were also coal combustion and soil, respectively, the third was refuse and the fourth was roadway dust.