Potential Updates to VIIRS Aerosol Optical Thickness Algorithm

The operational VIIRS Aerosol Optical Thickness (AOT) product compares well with MODIS (C5) and AERONET with accuracy and precision values of 0.01 and 0.06 over water, and -0.01 and 0.13 over land, but these performance metrics vary regionally and seasonally (Liu et al., 2014). To improve VIIRS AOT retrievals and expand the coverage to semi-arid/arid regions, we plan to update the algorithm. Potential updates to the VIIRS aerosol algorithm include more stringent internal tests for detecting unfavorable retrieval conditions, extending the spatial and measurement range of retrieved AOT, updating aerosol models to account for the non-spherical shape of dust, and introducing the scene dependent land surface spectral reflectance relationship. As a proof of concept, implementation of the updated algorithm is performed over an extended time period to evaluate its performance against the AERONET measurements, current operational VIIRS retrievals, and latest MODIS Collection 6 aerosol products. Preliminary results show extended spatial coverage, capturing of high AOTs during exceptional events, and improved performance.