VIIRS Version 2 Deep Blue Aerosol Products

NASA's Deep Blue aerosol project has developed global aerosol data records using consistent retrieval algorithms applied to various satellite sensors. The primary components of these data records are derived from the series of Visible Infrared Imaging Radiometer Suite (VIIRS) aboard the Suomi National Polar-orbiting Partnership (SNPP) and the National Oceanic and Atmospheric Administration or NOAA-20+ satellites as well as the Moderate Resolution Imaging Spectroradiometer (MODIS), among others. These instruments provide over 23 years of measurements with similar radiometric characteristics for aerosol retrievals. The algorithms used for the initial Version 1 SNPP VIIRS data set were based on the MODIS Collection 6.1 Deep Blue algorithm over land and Satellite Ocean Aerosol Retrieval (SOAR) algorithm over water. For VIIRS Version 2 data reprocessing, major updates have been made to the algorithm suite, including better accounting for effects of surface pressure, improved determination of surface reflectance, and the inclusion of fine-mode aerosol optical models to better represent anthropogenic aerosols over land. Cross-calibration gain factors are derived for the NOAA-20 VIIRS measurements to be consistent with the SNPP VIIRS, which allows the use of a unified algorithm package for both instruments. Comparisons against AERONET observations indicate that the Version 2 AOD data from SNPP VIIRS are significantly better than the Version 1 counterpart over land and slightly degraded over water in exchange for better spatial coverage. The AOD data from SNPP and NOAA-20 VIIRS are comparable, indicating that cross-calibration enables the creation of consistent aerosol data records using the series of VIIRS sensors. Aerosols are tiny particles suspended in the air that can come from natural sources like dust and sea salt, as well as human activities such as burning fossil fuels and industrial processes. Understanding these particles are important because they play a crucial role in the Earth's system through interactions with sunlight, clouds, and precipitation. These interactions are in turn closely related to global warming and cooling effects. Additionally, certain types of aerosols can harm human health when inhaled, leading to respiratory problems. Because of these important aspects, scientists have developed various tools to study aerosols. Satellite remote sensing is one such tool and have provided valuable data on global aerosol properties. This study describes updates made to a satellite remote sensing technique to enhance data quality. The new data sets are significantly improved compared to previous versions, indicating increased utility of the data sets. Introducing NASA's VIIRS Version 2 Deep Blue aerosol products Major updates in Deep Blue algorithm resulting in significant improvements in global aerosol optical depth retrievals Consistent data records between SNPP and NOAA-20+ VIIRS ensuring long-term data continuity