北京地区一次尘暴过程的气溶胶特征

本文讨论了1980年4月北京地区一次尘暴过程的气溶胶特征。气象资料分析表明,这次尘暴大风形成于新疆哈密及内蒙西部一带,开始大风区向东移动,到内蒙、河北一带又转向东南方向移动。利用325米气象塔和探空资料讨论了尘暴过程大气边界层的结构。 尘暴气溶胶浓度比平时要高一个量级,气溶胶中元素含量是用中子活化法分析的。分析结果说明,元素Eu和Ta只存在于尘暴气溶胶中,其它元素基本一样,但其含量变化较大。富集因子的计算表明,气溶胶中元素Se、As、Br、Sb主要来源于煤的燃烧。 从形成尘暴的气象背景的讨论和尘暴气溶胶中元素资料的分析,初步认为,这次尘暴气溶胶主要是由形成尘暴大风地区及其移动路经地区的沙土微粒被风带入高空混合而形成的。

SOME PROPERTIES OF THE AEROSOLS DURING A DUST STORM OVER BEIJING AREA

In this paper some characteristics of the aerosal in a dust storm occurring April 18-20, 1980,over Bering area were described. Analysis of meteorological data showed that the dust storm was formed in Hami area of Xingjiang Province and western part of Inner Mongolia. The strong wind area moved first toward east and then southeast when it reached central part of the Inner Mongolia and Hebei Province. By means of the 326-meter observation tower and radiosounding technique the Structure of atmospheric boundary layer was discussed for the dust storm.The aerosol Concentration of this dust storm much larger than usual by anorder of magnitude. Elemental concentration in aerosol was obtained by using neutron activation analysis. Analytical results indicated that elements Eu and Ta existed only in aerosol of this dust storm and the other elements appeared both in the normal aerosol and in the dust storm aerosol. Calculation of enrichment factor showed that elements Sc, As, Br, Sb came mainly from coal combustion.From discussion of the meteorological background of the dust storm formation and the analysis of the elements in aerosols it can be considered that the dust storm aerosol was made of soil particles brought and mixed by the strong wind into the atmosphere the particles are of the areas where the strong wind formed and passed.