Aerosol Optical Depth 

MODIS instrument on both Aqua and Terra satellites were used. AOD products are produced using different algorithms for different contents, namely absence of cloud, snow and ice cover over land (using Deep Blue and Dark Target algorithms) and ocean (using Dark Target algorithm). The spatial resolution of AOD datasets are 10×10 km and 3×3 km for MOD04 L2 and MOD04 3K & MYD04 3K, respectively. Both datasets were used to have a complete coverage. 

MODIS delivers 288 HDF files per day. However, since AOD information is not produced at night, only ∼ 144 files are used. This is also applied to the AOD dataset with “Cloud Coverage” where AOD information is obtained from the “Land and Ocean” Science Data Set (SDS). All data were merged according to WGS84 DATUM criteria and then converted to GEOTIFF format