Assessment of the Suomi NPP/VIIRS aerosol products using the collocated Aqua/MODIS aerosol products

Following the successful launch of the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument onboard the Suomi National Polar-orbiting Partnership (NPP) spacecraft, the VIIRS sensor collects daily global aerosol coverage to provide aerosol Intermediate Products (IPs) and Environmental Data Records (EDRs) to the user community. We validate the IPs and EDRs of the VIIRS Aerosol Optical Thickness (AOT) and Angström Exponent (AE) against the collocated well-characterized MODIS aerosol products from the NASA Earth Observing System (EOS) Aqua satellite. Both sensors are on the early afternoon orbit, which provides us an excellent opportunity to cross validate these operational satellite aerosol observations. Qualitative and quantitative assessments are conducted to characterize the VIIRS aerosol products. In the direct comparison, global aerosol maps of the collocated VIIRS-MODIS aerosol products are presented based on various match-up criteria based on quality flags, viewing geometries, AOT and AE data ranges etc. VIIRS AOT appears to match MODIS well over ocean, but is biased high against MODIS over land, except in desert regions. VIIRS AOT appears to correlate best with MODIS for high AE, and less well for coarse particle sizes. These results are based on a very limited analysis period of one month, and could change seasonally. The similarities and differences of the collocated VIIRS and MODIS aerosol products are discussed in details. Statistics of VIIRS vs. MODIS AOT where Δτ = τVIIRS -τMODIS;