北京地区PM10浓度空间分布特征的综合变分分析

利用2003年10月北京地区PM₁₀浓度流动观测资料和同期MODIS AOD(Aerosol Optical Depth)高分辨率遥感资料，采用卫星遥感地面观测变分订正处理方法，综合分析了北京地区PM₁₀浓度的空间分布特征以及机动车排放的影响效应。动态观测试验结果表明:北京城区大部分为轻污染区, 北京近郊区PM₁₀浓度高值区沿环路呈环状分布，其中北京西南部、南部和东北部污染较严重，北京城郊街区PM₁₀的空间分布受机动车排放的影响较大。MODIS卫星遥感资料分析表明:北京城区及近郊区AOD值较远郊区高得多，AOD空间分布场中存在虚假高值区，AOD非均匀分布特征不明显。采取点面结合综合观测研究思路，运用卫星遥感地面观测综合变分分析方法，可以取得客观订正的显著效果。经地面实测PM₁₀浓度变分订正后的AOD变分场可以较高分辨率信息描述北京地区AOD的非均匀分布特征，弥补地面PM₁₀浓度观测的缺陷。

Integrated Analysis on Spatial Distribution Characteristics of PM10 Concentration Based upon Variational Processing Method in Beijing

A study is carried out on the spatial distribution characteristics of PM10 mass concentration and effect of pollutants from motor vehicle emissions in the main streets,the ring roads which are located in urban districts and suburbs in Beijing,based on the integrated Atmospheric Pollution Field Experiments(BECAPEX,Beijing City Atmospheric Pollution Experiment)and variational processing methods by satellite retrieval data whose horizontal resolution is 1 km.The results show that PM10 mass concentration in the majority of urban area are low,especially in ancient building communities which are located inside the Second Ring Road and in large afforestation zone.High concentration areas of PM10 in suburb distribute along ring roads,and pollutions are much serious in the southwest,the south and the northeast of the suburbs.The above mentioned fact shows that the impact of vehicle emissions on PM10 concentration is very serious in blocks which are located in urban districts and suburbs.Before satellite retrieval data are corrected by variational processing method,the value of MODIS AOD(Aerosol Optical Depth)in urban districts and suburbs are much higher than that in exurb,there are inveracious high value areas of AOD in its spatial distribution field and its unsymmetrical spatial distribution characteristics is not obvious.AOD values in most exurbs are lower than that in urban districts and suburbs,especially in the northwest of the exurb.But AOD values in the southwest and the southeast of the exurb are relatively high.The remarkable corrected effect is obtained by using a point-plane integrated observation research technique and variational processing method by MODIS AOD retrieval data and corresponding observation data on the ground.AOD variational field with higher resolution information could be used to describe unsymmetrical spatial distribution characteristics in urban district and suburb detailedly,especially in exurb.This method can be used to make up the limitation of observation in exurbs.After satellite retrieval data are corrected by variational processing method,unsymmetrical spatial distribution characteristics of AOD value are more distinct and conformed with that of PM10 concentration.Inveracious high value areas of AOD distribution are removed.Orbicular distribution of AOD in near suburb is more obvious and its unsymmetrical distribution characteristics in exurbs are also more notable.The location and intensity of the above high and low AOD value areas are stable accordingly.