Using Remote Sensing Data To Estimate The Mass Concentration Of Particulate Matter In The Pearl River Delta Region

In the tropospheric, aerosol direct radiative forcing and indirect radiative forcing have an impact on the climate system. Meanwhile, aerosol particles, which will cause decreased visibility and has negative effects on human health, play an important role in polluting the air and affecting the quality of the atmospheric environment. As the rapid development of urbanization and industrialization process, the pollution of the atmospheric environment in Chinese cities is worsening, and the increasing haze weather has seriously affected the people’s ordinary life. According to the existing data, there are three region have been serious polluted in China, and the Pearl River Delta region is one of the three. Therefore, the study of aerosol particles in the material sense. Therefore, the study on the aerosol particle has an important significance.Ground-based measurements can obtain the ground-level mass concentration of the ground-level PM2.5 and PM10 information. Although ground-based measurements are generally considered to be accurate, they are representative for only relatively small areas around point stations. Often, the limited spatial coverage and irregular distribution of ground-based monitoring stations largely restrict the study on space-time dynamics of air pollution. By means of satellite remote sensing can compensate for the weakness, and it can provide more space information for the study of atmospheric pollution near the ground.Using the V5.2 aerosol retrieval algorithm from NASA, the AOT at a typical spatial resolution of 1 km over the Pearl River Delta region is retrieved; AOT and the Angstrom index, at a typical spatial resolution of 10 km, is retrieved as a level 2 product from the MODIS observation. The CE-318 AOT data, which is downloaded from the AERONET, is used to validate the MODIS AOT. The results show a good accuracy:the correlation coefficient between the retrieved AOT and CE-318 AOT reaches 0.5; and the correlation coefficient between the AOT obtained from MODIS aerosol product and CE-318 AOT is above 0.8.Based on the AOT, which is retrieved from satellite remote sensing and obtained from MODIS aerosol production, the characteristics of the temporal and spatial dynamics of the AOT over are analyzed. From the long term scale, the AOT over the Pearl River Delta region shows a periodic change:in winter the AOT decreases to the minimum, while it up to the maximum in summer. And the range of the AOT is 0-1.4. In space, the high-value of the AOT is mainly in cities such as Guangzhou, Foshan, Zhongshan, Shenzhen, Zhuhai, Dongguan, which is suffered heaver pollution.Direct comparison between satellite remote sensing AOT and ground-level mass concentration of the ground-level PM2.5 and PM10, the correlation coefficients between them are not good enough, and the R2 are 0.2588,0.2941 respectively. After vertical correction and RH correction, the correlation coefficients are 0.2625,0.2991 respectively. The incorporation of the ground-level temperature and wind speed is found to be significant in improving the model predictability, and the R2 are up to 0.362,0.445 respectively. According to the correlation analysis above, an empirical model is developed to predict the mass concentration of the ground-level PM2.5 and PM10coincident to remote sensing AOT by satellite overpass, at a region scale in the Pearl River Delta region. The decision coefficients of the model are 0.362,0.445 respectively. Using the PM data got from the rest in-situ station to validate the model, the model predicted values of ground-level PM2.5 and PM10 mass concentration air highly correlated with the actual observations.Based on the model built before, the mass concentrations of the ground-level PM2.5 and PM10 have been estimated. The mass concentration of the ground-level PM2.5 and PM10 varies periodically with time:in winter the mass concentration of the ground-level PM2.5 and PM10 increases to a high value, while it decreased to the minimum in summer. In space, the high value of the ground-level PM2.5 and PM10 mass concentration is mainly in the Foshan, Jiangmen, and Guangzhou. Compared with the Temporal-spatial variation of yearly means ground-level PM2.5 in the Pearl River Delta Regional Air Quality Monitoring Network-A Report of Monitoring Results over the Pearl River Delta region, the estimated result has the similar spatial distribution. The empirical model provides a cost-effective approach for obtaining supplemental ground-level PM2.5 and PM10 mass concentration information in addition to the ground-based monitoring station measurement.