SHEN Yang1, ZHANG Lianpeng1, *, FANG Xing1, ZHAO Zhuowen2
(1. School of Geography, Geomatics and Planning, Jiangsu Normal University, Xuzhou 221116, China;
2. Jiangsu Institute of Surveying and Mapping, Nanjing 210013, China)
Abstract: The relationship model of PM2.5 concentration and AOD (aerosol optical depth) was constructed, the annual changes of vertical corrected AOD (AOD/H) and moisture corrected PM2.5 concentration (PM2.5 * f(RH)) and their correlation, which could be used as a reference for air quality evaluation, in the Xuzhou city were analyzed. The correlations between AODs and PM2.5 concentrations in different seasons were investigated on the basis of MODIS AOD, PM2.5 concentration dataset and related meteorological data from 2014 to 2017, and five different fitting methods were applied to explore correlations of AOD/H and PM2.5 * f(RH) in different seasons. The empirical mode decomposition was used to analyze periodic variations of AOD/H and PM2.5 * f(RH). The results showed that no correlation was found between original AODs and PM2.5 concentration data, but AOD/H and PM2.5 * f(RH) correlated notably. The power model was the optimal fitting model for predicting PM2.5 concentrations based on monitored data of PM2.5 * f(RH) in Xuzhou, the correlation coefficients were 0.752, 0.650, 0.808 and 0.942 for the four seasons, respectively. The annual trends of AOD/H and PM2.5 * f(RH) were highly covaried with R2=0.888, and their highest values were showed in winter, and gradually decreased to the minimum values around June in summer, and then gradually increased throughout autumn. In summary, this study demonstrated that AOD is an effective proxy to estimate the concentration of PM2.5 and that AOD/H is a good index for describing the annual changes of PM2.5 * f(RH) in the Xuzhou city.
Key words: PM2.5; AOD (aerosol optical depth); empirical mode decomposition; correlation analysis; Xuzhou
EARTH AND ENVIRONMENT Vol.47, No.1, Tot No.327, 2019, Page 34-42