摘要
为了研究华北平原北部区域不同类型站点光化学前体物的共性与差异,在华北平原北部地区西南-东北主导风向上选取间距大于100km的3个站点,即中国气象局（CMA）、上甸子（SDZ）和固城（GCH）依次代表北京城区、华北本底地区和相对污染的农村地区,进行了近地面NOx和CO观测。结果表明,2008年6月至2009年5月,CMA、SDZ和GCH 3站NOx体积分数的年均值依次为（42.4±21.8）×10-9、（13.8±5.5）×10-9和（26.9±15.2）×10-9,CO体积分数的年均值依次为（1.13±0.37）×10-6、（0.67±0.17）×10-6和（1.11±0.62）×10-6。3站的NOx月均值体积分数及CMA、GCH两站的CO月均值体积分数呈现出冬季高夏季低的特点,而SDZ站的CO 6月均值体积分数（1.03×10-6）为一年中最高。SDZ站的NOx和CO体积分数在中午12时前后出现一个低谷,比CMA和GCH站的提前3~4 h,此后呈上升趋势,体现了午后西南风输送对SDZ站的影响。尽管不同的源排放和大气输送影响导致3站的NOx和CO体积分数在日变化特征上有所差异,但3站的NOx和CO日平均体积分数之间存在极其显著的相关性,体现了区域性污染和气象条件共同影响的特征。
The article is devoted to an investigation of the variation characteristics of NOx and CO at three sites in Beijing and its surrounding areas in hoping to find the similarity and dissimilarity in the characteristic features of the ambient NOx and CO emission in different kinds of regions in the North China Plain. For the research purpose, we have observed the mixing ratios of CO and NOx in the surface layer air at the three sites, which are over 100 km apart from each other and parallel-aligned with the prevailing SW - NE wind directions. The three sites are China＇ s Meteorological Administration （CMA）, the Shangdianzi station （SDZ）, and the Gueheng station （GCH） , representing typically the urban area of Beijing, the regional background area of the North China plain, and the rather seriously polluted rural area in China North, respectively. The results of our investigation show that from June, 2008 to May, 2009, the annual average concentrations of NOx at CMA, GCH, and SDZ were （42.4 ±21.8） × 10^-9, （26.9 ± 15.2） × 10^-9, and （13.8± 5.5） × 10^-9, respectively, and those of CO were （1.13 ±0.37） × 10^-6, （1.11 ± 0.62） × 10^-6, and （0.67± 0.17） × 10^-6, respectively. At CMA and GCH, the monthly average concentrations of NOx and CO reached the corresponding maximum in winter and minimum in summer, whereas the highest monthly average concentration of CO at SDZ was observed in June （1.03 × 10^-6）. The concentrations of NOx at CMA, GCH, and SDZ turned to be 3.4, 3.6, and 1.8 times higher in winter than those in summer, respectively. The concentrations of CO at CMA, GCH, and SDZ were 1.8, 2.9, and 0.8 times higher in winter than those in summer, respectively. The average diurnal variations indicated that the CO and NOx concentrations of SDZ decreased to their minimum around noon, about 3 - 4 h earlier than those of GCH and CMA, and then increased gradually till evening, in response to the impact of pollutant transport on the gas concentrations of SDZ. The above dissimilarities in the diurnal variations can probably account for the different effects of emission sources and the airmass transport on the concentrations of pollutants at the three sites. The time series of the daily average CO and NOx concentrations show great similarities among sites, revealing that the characteristic features were influenced by the common regional pollution and similar meteorological conditions. The observation data we have gained indicate fairly high CO level in the North China Plain in summer, which was probably caused by the outdoor combustion of large amount of wheat straw.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2014年第6期252-257,共6页
Journal of Safety and Environment
基金
中国气象科学研究院基本科研业务费项目(2011Z003)
公益性行业(气象)科研专项经费项目(GYHY201106050)
关键词
环境学
北京
NOx
CO
区域性污染
environmentalology
Beijing
NOx
CO
regional pollution
