Ground Verification And Analysis Of Multi-source Satellite Remote Sensing Aerosol Data In Xuzhou Area

This thesis takes the Xuzhou area as the research object,supplemented by ENVI,IDL,MATLAB,Arcgis,etc.,using ground-based CE-318 sun photometer observation AOD to verify the AOD products of Terra,Aqua,COMS and Himawari-8 satellites.Based on the verification results,the spatial distribution of AOD in Xuzhou region was analyzed.In addition,the AOD,Angstrom index,SSA,g obtained from the ground-based CE-318 photometer were used to analyze the haracteristics of long-term changes in characteristics of aerosol optics in Xuzhou region from July 2013 to February 2017.The verification results of satellite AOD in Xuzhou area show that:(1)MODIS AOD products have good applicability in Xuzhou area,but there is a consistent overestimation phenomenon,and the overestimation phenomenon in spring and summer is relatively obvious,both being about 0.2;(2)GOCI AOD products have large residual error and their applicability in Xuzhou area is general;(3)AHI AOD inversion has certain systematic errors,there is a serious underestimation phenomenon in Xuzhou area and the applicability is relatively poor,underestimates above 0.2 in each season.The research on the spatial distribution of satellite AOD in Xuzhou area shows that:(1)The color gamut of AOD pixels in Xuzhou area is relatively similar to those surrounding Beijing,Tianjin,Hebei,Jiangsu,Shandong,Henan and Anhui;(2)The value range of the AOD high value zone is around 0.8,mainly concentrated in the north of Fengxian,south of Peixian,and southwest of Pizhou City,while the value range of the low value region is around 0.2,mainly concentrated near the downtown area and southwest of Xinyi City.The value of AOD in other regions are stable at about 0.5;(3)In Xuzhou areas which have high values of AOD are widely distributed in spring,covering most areas of Fengxian,Peixian,Pizhou,Jiawang,Tongshan,and Suining County,as well as the some areas in Xinyi.In the summer,the value range of areas which have the high value AOD have gradually narrowed,and the range of autumn AOD narrowed to the four smaller areas which include the north of Fengxian County,the south of Pei County,the southwest of Pizhou City and the northeast of Xinyi City.The winter range further narrowed,mainly in terms of the northwest of Fengxian County,the southwest of Pei County,and the northwest of Pizhou City,but the value range has increased compared with summer and autumn.The analysis of long-term changes in aerosol optical properties in Xuzhou area shows that:(1)AOD in Xuzhou has been decreasing year by year from 2014 to the present,and there has been no significant difference among AOD seasons;(2)There has been no change in the particle size of pollutants in Xuzhou since 2014,the proportion of non-natural sources is stable.In summer,fine-scale urban-industrial aerosols dominate the particles,while spring aerosol particles use coarse-grained natural-source large particles as the main control particles;(3)The annual variation of SSA is small,and in each season have the little difference.Generally,there are more weakly absorbing particles in summer and autumn,and more moderate absorbing particles in spring and winter.;(4)The asymmetric factor g has a small change range,and the average change amplitude is only 0.5%,the aerosols in the four seasons in Xuzhou are all with forward scattering ratio higher than back scattering ratio.