北京地区3500m高空内污染物的时空分布特征

利用2007~2010年北京地区3500m高空内飞机探测的大气污染物(NOx、SO2 、CO和O3)数据资料,分析其时空分布特征.结果表明: 在4~11月期间,NOx、SO2和CO月均值有比较明显的一致性变化规律,NOx、SO2 和CO月均值随高度增加而减小,而O3月均值随高度增加,出现先增大后减小的变化规律.温度较高月份(7~10月)值较小,而温度较低月份(4~6月、11月)值较大,但O3月均值季节变化规律为夏季5~9月的较大,春秋季4月、10~11月的较小.不同的高度大气污染物浓度白天逐时变化并不一致,其变化率是1500m以下的比1500~3500m的明显高.北京地区大气污染物区域分布特征是,除城区四环明显较高外,城区正北面、西南面(北京-保定方向)、东南面(北京-天津方向)较高,西北面(北京-张家口方向)较低.

Temporal and spatial distribution of atmospheric pollutants by aircraft sounding in 3500m altitude of Beijing area

Based on the aircraft sounding concentrations data of nitrogen oxides (NOx), Sulfur dioxide (SO2), Carbon monoxide (CO) and ozone (O3) over Beijing area from 2007 to 2010, the temporal and spatial distribution of atmospheric pollutants concentrations from the ground surface to 3500m altitude were studied. Vertical profiles of monthly average concentrations of NOx, SO2 and CO were in good agreement during April to November, that decreased with the raising of altitude, but concentrations of O3 first increased and then decreased. Low concentrations of NOx, SO2 and CO appeared in the high temperature months (July to October) and their high concentrations appeared in the low temperature months (April to June, November), and O3 concentrations were lower in spring and autumn (April, October to November), but that were higher in summer (May to September). In a daytime, pollutants concentrations at different altitude change with time were not consistent, and hourly change of pollutants concentrations below 1500m altitude, were significantly higher than that in 1500~3500m altitude. The characteristic of regional horizontal distributions of pollutants was that higher concentrations appeared in the urban area of Beijing, higher pollutants concentrations areas were in the northern, southwestern (Beijing-Baoding direction) and southeastern sections (Beijing-Tianjin direction), lower pollutants concentrations areas were in the northwestern sections (Beijing-Zhangjiakou direction).