Aerosol Over Nanjing Area Determined From Satellite And Foundation Measurements And Analysis

In the rapid development of modern China process, the atmospheric environment gradually poor, making it as the current people attach great importance to one of the environmental topics. Aerosol research, for the observation and treatment of air pollution is very important. We use CE-318 sun photometer,MPL lidar and satellite to measure aerosols in Nanjing, and use spectral light extinction method, the Fernald method and MODIS Dark Dense Vegetation method(DDV),respectively, to calculate aerosol optical thickness(AOD).The spatial distribution maps of AOD from satellite shows AOD is higher in the vicinity of the Yangtze River and urban district (in addition to the Laoshan,Sun Yat Sen and other mountainous areas). By comparing three kind AOD datas between March and September, we found the difference of AOD is not large, AOD values calculated from satellite and lidar are relatively reliable. Calculated AOD values, in march 3rd, from CE-318 sun photometer, MPL lidar and satellite data were 0.455, 0.289 and 0.4 respectively and in March 6th, were 0.373, 0.267, 0.25 respectively, in site location(Nanjing University of Information Science and Technology, 118.7°E, 32.2°N). In addition,There are two common types of changes AOD observation area, the first shows:AOD is high in the morning and evening, and is low at noon; the second shows:AOD is low in the morning and high in the evening. In a haze event, MPL lidar data show that the 532nm band, haze before the AOD is about 0.2 to 0.3, the haze of the period of 0.6 to 1.0, after the haze of 0.4 to 0.6. Moreover, the results of the lidar data varied so much with time, and lidar can be measured in the cloudy weather to detect aerosol. This paper presented the mean value of AOD by lidar below the 9km are most about 0.3. In March 3rd and March 6th, below 2km is dirty, it should be some aerosols, above 6km is relatively clean,it should be some clouds. Compared with the solar photometer, the relative error is 74.8%, the minimum is 3.4%, and the average relative error is 27.35, which is much lower than that of MOD04 aerosol product(average relative error is 79%). The results of the lidar are 40.9% and 5.3%,respectively, compared with the solar photometer. The three kinds of observation modes have their own characteristics in terms of accuracy, spatial resolution and temporal resolution. If they can be used together, the aerosol observation in the future three-dimensional space can be promoted.