Retrieval of Urban Aerosol Optical Depth from Landsat 8 OLI in Nanjing, China

Aerosol is an essential parameter for assessing the atmospheric environmental quality, and accurate monitoring of aerosol optical depth (AOD) great significance in climate research protection. Based on Landsat 8 Operational Land Imager (OLI) images MODIS09A1 surface reflectance products under clear skies with limited cloud cover, we retrieved AODs Nanjing City from 2017 to 2018 using combined Dark Target (DT) Deep Blue (DB) methods. The retrieval accuracy was validated by in-situ CE-318 measurements MOD04_3K products. Furthermore, analyzed spatiotemporal distribution discussed a case high AOD distribution. results showed that: (1) Validated data, correlation coefficient (R), root mean square error (RMSE), absolute (MAE) were 0.874 0.802, 0.134 0.188, 0.099 0.138, respectively. Hence, DT DB algorithms used this study exhibited higher performance than MOD04_3K-obtained (2) Under static stable meteorological conditions, average annual 0.47. At spatial scale, relatively values north west, low south, lowest center. seasonal highest summer, followed spring, winter, autumn. Moreover, changes significantly summer other three seasons, little differences among autumn, winter. (3) characteristics Nanjing, caused large area external pollution local conditions discussed, indicating that it could provide extra details analyze air sources fine resolution like OLI.