2013年南京市PM2．5时空分布规律

[目的]探讨利用站点实测PM2．5数据与NASA MODIS气溶胶光学厚度（AOD）研究南京PM2．5时空分布规律的可行性。[方法]将2013年南京市实测PM2．5数据进行空间插值，基于MODIS数据利用暗像元法反演得到的气溶胶光学厚度与2013年南京市PM2．5质量浓度进行相关性分析。光学厚度引入季节变化的气溶胶标高，并用湿度因子订正。[结果]订正后的二者相关系数均有明显提高。站点实测PM2．5通过空间插值可以在一定程度上反映南京市PM2．5的空间分布规律，PM2．5主要集中于鼓楼、建邺等经济发达区域，栖霞区域相对最低。 PM2．5夏季较低，冬季较高。校正后的AOD与站点实测PM2．5的相关性达0．426，远高于未进行校正的0．214。[结论]在中小尺度下反演的AOD能够在一定程度上表征PM2．5的浓度变化，通过更为精确的AOD反演方法能够在时空两方面反映PM2．5的时空变化规律，使城市PM2．5污染治理更加科学合理。

Spatio-temporal Distribution of PM2.5 in Nanjing in 2013

Objective] To explore the feasibility of study on the spatio-temporal distribution of PM2.5 in Nanjing by PM2.5 data collected in sta-tion and NASA MODIS aerosol optical depth (AOD).[Methods] The in-site PM2.5 data of Nanjing in 2013 was interpolated into spatial inter-polation.AOD was extracted by the dark like element method ( DDV) algorithm based on MODIS data.Finally the correlation of PM2.5 mass concentration was analyzed and AOD seasonal variation of aerosol elevation was introduced into AOD.Besides, the humidity factor was applied to correct the AOD, and the correlation coefficient of two revised values has been improved obviously.[ Results] The results indicated that the spatial interpolation PM2.5 can reflect the spatial distribution of PM2.5 in Nanjing.PM2.5 is mainly concentrated in Gulou and Jianye districts, and the concentration of PM2.5 is lowest in Qixia District.The temporal distribution of PM2.5 is higher in winter and lower in summer.The cor-relation between revised AOD and in-situ PM2.5 is up to 0.426, higher than that without correction.[Conclusions] AOD can characterize the concentration change in PM2.5 to a certain extent in the small and middle scale.The more accurate urban PM2.5 pollution distribution monito-ring system based on AOD will make the spatio-temporal distribution of PM2.5 more accurate, so as to make the PM2.5 pollution control more scientific and reasonable.