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NOAA Climate Data Record (CDR) of AVHRR Daily and Monthly Aerosol Optical Thickness (AOT) over Global Oceans, Version 4.0
The product is the aerosol optical thickness (AOT) at 0.63 micron, which is retrieved from NOAA PATMOS-x AVHRR+HIRS level-2B orbital radiance and cloud CDR products. The retrieval is performed for selected spatial (0.1 by 0.1 degree) and temporal (1 time per day per satellite) resolution in cloud free conditions during daytime. The final product is daily averaged from all satellite retrievals and in a 0.1 by 0.1 degree equal angle grid (total 1800x3600 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 none-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 final CDR AOT products include daily and monthly products.