A high-resolution global dataset of aerosol optical depth over land from MODIS data

To improve the spatial resolution of the global aerosol optical depth (AOD) distribution, a new method for AOD retrieval is proposed over land in this paper. A monthly Global Land Surface Reflectance Database (GLSRD) was constructed using the long time serious of MODIS surface reflectance product (MOD09A1) and used for the surface reflectance estimation over land for AOD retrieval. A seasonal Global Land Aerosol Type Database (GLATD) was also built based on the MODIS aerosol product (MOD04) and used for providing the aerosol types over land in AOD retrieval. Thus, the AOD global dataset with 1 km resolution was produced and was validated against with the AERONET ground-based AOD measurements located in the global 172 stations over land. Results showed that the AOD retrievals are highly consistent with AERONET AODs and showed an overall better precision over both dark and bright areas.