Spatial structure and scale feature of the atmospheric pollution source impact of city agglomeration
Spatial structure and scale feature of the atmospheric pollution source impact of city agglomeration
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DOI：
10.1360/05yd0030
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发表时间：
2005-06
影响因子：
5.7
通讯作者：
Xu Xiangde;Zhou Xiuji;Shi Xiaohui
中科院分区：
文献类型：
--
作者：
Xu Xiangde;Zhou Xiuji;Shi Xiaohui
北京及周边地区大气污染影响域的空间结构与多尺度特征利用北京城市大气污染观测试验（BECAPEX）冬季城市建筑物集合边界层大气污染动力化学过程观测资料，对北京市（一个快速发展的城市群）进行了剖析利用2003年2月和夏季（8月）相关气象要素和卫星反演气溶胶光学厚度（AOD）等综合资料，进行了"点-面"空间结构的动力-统计综合分析。结果表明，冬、夏季不同污染源对大气污染物组分特征的贡献存在显著差异，统计模型的主成分分析（PCA）结果也表明，冬季气溶胶颗粒物组分结构以SO2和NOX为主，夏季则以CO和NOX为主。北京城市不同观测点冬、夏季近地层大气动力、热力结构及建筑群上边界各种污染物形态均呈现出"同相"变化及其"入流域"的空间尺度特征。功率谱分析（PSA）结果表明，冬夏季颗粒物浓度的周期谱与大气风场的周期谱一致，冬季以长周期为主，夏季以短周期为主，揭示了冬夏季大气环流的季节尺度特征对大气污染变化周期的影响。通过对城市热环境异质性的分析发现，北京地区城市热岛效应的多尺度效应与高层建筑面积的异质性扩张有关。在城市大气动力热力特征空间结构中，建筑群边界层湍流尺度特征对城市大气污染的多尺度特征有重要影响。通过对晴空条件下中分辨率成像光谱仪（MODIS）AOD-地面PM_（10）的变分分析场和污染源追踪的相关合成风矢量场的综合分析，认为北京冬季大气污染气溶胶粒子的排放源可远距离追踪到河北、山东、天津等地的南周边大尺度空间范围内，AOD高值区的空间分布与居民家庭数（受热面源）高值区的空间分布相关。冬夏季大气颗粒物后向轨迹特征具有相似的多尺度特征，反映了不同季节污染源空间分布的尺度特征差异。城市大气污染物（UAP）的周边源轨迹路径主要来自北京郊区的固定工业面源或加热面源，冬季周边源的扩散和输送距离大于夏季。上述结论描述了UAP源影响和大气动力结构引起的多尺度空间影响域和季节特征。冬季TOMS气溶胶光学厚度（AOD）的高值区位于北京地区及其南周边地区，呈南北带状分布，反映了周边地形对区域尺度大气污染源扩散的动力作用。研究表明，北京及周边“山谷”地带冬季大气污染程度与南部周边地区污染源密切相关;北京及周边地区冬季气溶胶光学厚度和日照时数的显著"反相"变化特征，以及北京地区低云、雾日、气溶胶反映了该地区气溶胶影响的局地气候效应。此外，还分析了流域尺度大气干、湿沉降分布对密云水库区域水体的影响，揭示了夏季水、土壤和大气污染源的多尺度空间结构对密云水库水质的可能影响。
The spatial structure and multi-scale feature of the atmospheric pollution influence domain of Beijing and its peripheral areas (a rapidly developed city agglomeration) is dissected and analyzed in this paper on the basis of the atmospheric pollution dynamic-chemical process observation data of the urban building ensemble boundary layer of the Beijing City Air Pollution Observation Experiment (BECAPEX) in winter (February) and summer (August) 2003, and relevant meteorological elements and satellite retrieval aerosol optical depth (AOD), etc. com- prehensive data with the dynamic-statistical integrated analysis of “point-surface” spatial struc- ture. Results show that there existed significant difference in the contribution of winter/summer different pollution emission sources to the component character of atmospheric pollution, and the principal component analysis (PCA) results of statistical model also indicate that SO 2 and NO X dominated in the component structure of winter aerosol particle; instead, CO and NO X dominated in summer. Surface layer atmospheric dynamic and thermal structures and various pollutant species at the upper boundary of building ensembles at urban different observational sites of Beijing in winter and summer showed an “in-phase” variation and its spatial scale feature of “in- fluence domain”. The power spectrum analysis (PSA) shows that the period spectrum of win- ter/summer particle concentration accorded with those of atmospheric wind field: the longer pe- riod was dominative in winter, but the shorter period in summer, revealing the impact of the seasonal scale feature of winter/summer atmospheric general circulation on the period of at- mospheric pollution variations. It is found that from analyzing urban area thermal heterogeneity that the multi-scale effect of Beijing region urban heat island (UHI) was associated with the het- erogeneous expansion of tall buildings area. In urban atmospheric dynamical and thermal char- acteristic spatial structures, the turbulent scale feature of the urban boundary layer (UBL) of ar- chitectural complexes had important impact on the multi-scale feature of urban atmospheric pollution. The comprehensive analyses of the variational analysis field of Moderate Resolution Imaging Spectroradiometer (MODIS) AOD-surface PM10 under the condition of clear sky and the correlation resultant wind vector field for pollution source-tracing suggest that the emission sources for winter Beijing atmospheric pollution aerosols particle might be remotely traced to the south peripheral greater-scale spatial range of Hebei, Shandong, Tianjin, etc., and the spatial distribution of the high value area of AOD was associated with that of the high value area of resident family number (heating surface source). The backward trajectory feature of winter/ summer air particles exhibits analogous multi-scale feature, and depicts the difference in the scale feature of the pollution sources spatial distribution in different seasons. The peripheral source trajectory paths of urban atmospheric pollution (UAP) mainly come from the fixed indus- trial surface source or heating surface source in the outskirt of Beijing, and the diffusion and transport distance of peripheral sources in winter is larger than one in summer. The above con- clusions depict the multi-scale spatial influence domain and seasonal features caused by UAP source influence and atmospheric dynamical structure. The high value area of the winter Total Ozone Mapping Spectrometer (TOMS) AOD lay in the Beijing region and its south peripheral area, an S-N zonal pattern, which reflects the dynamical effect of peripheral topographic pattern on the diffusion of regional scale atmospheric pollution sources. Study suggests that the extent of winter atmospheric pollution within the “valley” megarelief in Beijing and periphery was close related with the pollution emission sources of the south peripheral area; and the significant “anti-phase” variation feature of winter AOD and sunshine duration in Beijing and its peripheral areas, and the regional scale correlation of low cloud cover, fog days, and aerosols reflects the local climatic effect of aerosol influence in this region. Besides, analysis of the impacts of at- mospheric dry/wet deposition distributions within a valley-scale on the regional water body of Miyun reservoir also reveals the possible influence of the multi-scale spatial structure of summer water, soil and atmospheric pollution sources on the water quality of Miyun reservoir.