乌鲁木齐大气污染物的空间分布及地面风场效应

通过对1999—2001年乌鲁木齐市监测站3种污染物浓度的分析,比较深入地掌握了乌鲁木齐市区不同季节污染物的空间分布状况,得出城市首要污染物是PM10,污染物主要在乌鲁木齐市天山区堆积;利用乌鲁木齐城郊地面风场资料、海拔1 000 m高度探空风场资料分析了地面风场常年特征、季节变化特点,得出冬季城中偏南和偏北有辐合性流场,夏季整个城市为辐散性流场;近地层冬季静风频率高;结合污染物的空间分布和高空风场特征,从一个方面解释了乌鲁木齐冬季、夏季污染物浓度变化的原因。

Spatial Distributions of Atmospheric Contaminations and Effect of Surface Wind in Urumqi

In this paper we analyzed the spatial distributions of atmospheric contaminations in different seasons around Urumqi city by using three kinds of contamination concentration data which were observed during 1999—2001 at Urumqi Monitoring Stations. The results show that the predominant contamination is PM10 and the largest concentration area is Tianshan district. We also analyzed the mean annual characteristics and seasonal variations of surface wind and high level wind at 1 000 m. We found that in winter, there are convergence wind flows in southern and northern city, whereas in summer the air flows are divergent within the whole city. The frequency of stationary wind in winter is relatively high. With these conclusions we can explain the reasons of variation of contaminations concentrations of Urumqi in winter and summer from an aspect.