Validation and Expected Error Estimation of Suomi-NPP VIIRS Aerosol Optical Thickness and Angström Exponent with AERONET

The Visible Infrared Imaging Radiometer Suite (VIIRS) onboard of the Suomi National Polar-orbiting Partnership (S-NPP) satellite provides daily global aerosol observations since Oct 2011. Comparing VIIRS aerosol products to AERONET measurements plays a vital role in validating the maturity levels of the VIIRS aerosol products. The study applied the multi-sensor aerosol product sampling system (MAPSS) to compare the Suomi-NPP VIIRS aerosol optical thickness (AOT) and Angström exponent (AE) environment data record (EDR) and intermediate product (IP) to the AERONET measurements. The accuracy and precision of the VIIRS aerosol products, as determined by the comparison with AERONET measurements, were evaluated against JPSS-1 performance evaluation threshold values for Validated Stage maturity assessment. Expected errors of the S-NPP VIIRS AOT and AE retrievals in reference to both AERONET measurements and VIIRS observations were estimated and demonstrated. The deviation of the VIIRS aerosol retrievals from AERONET were presented with discussions on data uncertainties, such as dependance on viewing geometries, regional and seasonal characterizations, snow and vegetation coverages, etc. Based on the assessment, the S-NPP VIIRS AOT EDR over land reached Validated Stage II since Jan 23, 2013 and AOT EDR and AE EDR over ocean reached Validated Stage I since May 2, 2012 excluding the processing error period Oct 15-Nov 27, 2012. The findings from the validation and expected error estimation of the S-NPP VIIRS aerosol products will aid in the improvement of the VIIRS aerosol products as we transition from S-NPP to JPSS-1.