乌鲁木齐市夏季大气对流层NO_2垂直柱浓度特征研究

Study on characteristics of tropospheric NO_2 vertical column densities in summer in Urumqi

为掌握乌鲁木齐市夏季大气对流层NO2垂直柱浓度(VCD)变化特征,2013年6—8月利用地基多轴差分吸收光谱仪,依据该市南高北低的地形和常年主风向(西北风/东南风),分别在商业区、生活区、工业区和农田区进行大气对流层NO2VCD的监测。结果表明:(1)乌鲁木齐市夏季大气对流层NO2VCD均值为5.70×1015 molec/cm2,早、晚的浓度较高;随南高北低地势,大气对流层NO2VCD呈现南部>北部>中部的趋势;从不同功能区看,商业区>农田区>工业区>生活区;(2)比较不同天气条件下的大气对流层NO2VCD,晴天的浓度大于多云的浓度;且多云条件的日变化幅度小于晴天,但在不同天气条件下大气对流层NO2VCD在市区不同空间点各有差异;(3)功能区因素、地形地貌因素、主要污染物因素、气象因素和风场效应等的共同作用是乌鲁木齐市夏季大气对流层NO2VCD变化特征空间差异的原因。

The tropospheric NOz vertical column densities （VCD） had been monitored by multi axis differential optical absorption spectroscopy in summer in Urumqi. The monitoring points had been collocated from north to south at downtown,living area, industrial area and farming area, respectively. The results showed that： The mean tropospheric NO2 VCD was 5.70 × 10^15 molec/cm^2 in Urumqi in summer,and had a higher value at morning and evening. Through the topography-high in the south low in the north-the mean tropospheric NO2 VCD had a feature showing southern region^northern region〉middle area. From the perspective of urban space structure, it was downtown〉 farming area^industrial area〉living area. Under the different weather conditions,the main tropospheric NO2 VCD of sunny day was higher than cloudy day,the diurnal variation amplitude of cloudy day was less than that of sunny day, and they had some differences in each monitoring point. The reason of NO2 VCD＇s variation,distribution and difference in summer in Urumqi was in effects of different functional area,landform, main pollution, meteorologic elements and wind field.