兰州地区大气臭氧时空变化及影响因素研究

本文采用OMI臭氧遥感数据,结合甲醛垂直柱浓度、气象数据以及经济数据,分析了2005~2015年兰州地区臭氧柱浓度时空变化格局,并探索了影响臭氧的新气象因子,总结达到臭氧污染的日照、气压等气象条件,确定影响臭氧柱浓度的主要人为源并确定其限域。结果表明:1)2005~2015年夏季柱浓度值最高,冬季、秋季次之,春季最低;夏季波动幅度最大,其余三季波动幅度较小且平稳。2)11年中,臭氧柱浓度具有较大的波动。2005年至2010年快速增长到最高值331.997 DU。2010年之后,臭氧柱浓度缓慢下降,2014年起有回升趋势。3)OMI遥感数据具有较高的可靠性,并根据AQI的线性关系划分了臭氧柱浓度的污染等级。结果指示了11年大气臭氧空间变化,2005~2009年5年间研究区全区空气质量一直处于良,2010年全区轻度污染,后两年污染逐渐减弱,2013~2015年全区恢复至良。4)根据兰州发展的趋势以及周边城市的关系,划分了兰州经济圈及功能区,并结合臭氧柱浓度空间分布图得出臭氧污染与经济特征的密切关系。5)正弦模型拟合后臭氧柱浓度变化趋势呈不明显的周期性,说明臭氧的人为来源贡献较大。6)创新探索影响臭氧污染的新气象因子(日照、气压等参数),并确定其重要人为源限域。

Temporal and Spatial Variation of Atmospheric Ozone in Lanzhou and Its Influencing Factors

This paper investigated temporal and spatial variation patterns of ozone column concentration during 2005-2015 in the Lanzhou area based on the OMI remote sensing data, and combined with vertical column concentration of formaldehyde, meteorological data and economic data. The new meteorological factors affecting ozone were explored, and the meteorological conditions such as sunshine and atmospheric pressure were summarized. The main anthropogenic sources affecting the concentration of ozone column were determined and their limits were determined. Results demonstrated that, 1) during 2005-2105, the highest column concentration of year presented in summer, followed by in winter and in autumn, and the lowest in spring, with a large fluctuation in summer and little and stably fluctuations in other three seasons; 2) the ozone column concentration fluctuated significantly during the 11 years, it increased rapidly from 2005 and peaked in 2010 (331.997 DU), then decreased slowly until 2014, and showed an increasing trend since that; 3) the OMI remote sensing data showed high reliability according to ground ozone monitor data, and the pollution grade of ozone, which was divided according to the linear relationship of AQI, indicated the air quality of the study area was good during 2005 to 2009, was lightly polluted in 2010, and then improved in the following two years, and became good from 2013 to 2015; 4) the economic circle and functional area of Lanzhou were defined according to the development trend of Lanzhou and the relationship between the surrounding cities, and then the relationship between ozone pollution and economic characteristics was analyzed; 5) the sinusoidal model fitting found no obvious periodicity in the trend of ozone column concentration, indicating the large anthropogenic contribution of ozone; 6) the new meteorological factors of ozone pollution in Lanzhou were explored, i.e. atmospheric pressure and other factors, and the important anthropogenic sources were determined.