NOAA Climate Data Record (CDR) of AVHRR Daily and Monthly Aerosol Optical Thickness over Global Oceans, Version 1.0 (Version Superseded)

Note: This dataset version has been superseded by a newer version. It is highly recommended that users access the current version. Users should only use this version for special cases, such as reproducing studies that used this version. This NOAA Climate Data Record (CDR) of aerosol optical thickness (AOT) at 0.63 micron is retrieved from operational AVHRR orbital pixel level observations in the Level-1B Global Area Coverage (GAC) dataset. The retrieval is performed for selected spatial (8-km) and temporal (1 time per day) resolution in cloud free condition during daytime over global oceans. The final product is mapped into 0.5 by 0.5 degree equal area grid (total 165018 grids over the globe). Due to the relatively large uncertainties associated with surface reflectance over water glint area and land surface as well as limited AVHRR retrieval channels, the current algorithm only performs retrieval over non-glint water surface (specifically at the anti-solar side of the orbit and viewing angle is larger than 40 degree away from the specular ray). The retrieval products include a daily and monthly mean product and cover the period from 1981 to 2009. Daily and monthly mean data files are grouped by ascending and descending node by satellite.