Quasi-Global Maps of Daily Aerosol Optical Depth From a Ring of Five Geostationary Meteorological Satellites Using AERUS-GEO

Geostationary meteorological satellites are recently receiving a great deal of attention from the aerosol remote sensing community due to their increasingly advanced performances including their ability to acquire multiple views of the Earth per day. However, this type of observing systems are limited by their partial coverage of the globe, which makes them inappropriate for monitoring long-range-transported particles or assimilating the derived aerosol products into global atmospheric models. This shortcoming is overcome in this pioneering investigation thanks to the simultaneous use of the geostationary satellites GOES-17, GOES-16, Meteosat-11, Meteosat-8, and Himawari-8. The combination of these five spacecrafts (herein referred to as GEO-ring) covers the full globe except for polar regions, which are not seen from geostationary orbit. Data acquired by the GEO-ring in 2020 are processed by the algorithm AERUS-GEO to provide quasi-global maps of daily aerosol optical depth (AOD). These data are proved to be accurate with respect to AERONET ground measurements. The potential of the GEO-ring for aerosol science is then demonstrated. First, retrieved AOD maps are proved to be potentially useful for global aerosol forecasting due to the improved Earth coverage of the GEO-ring with respect to the polar orbiting satellites Terra/Aqua (51.4% vs. 26.6%). Second, retrieved aerosol data are used to track long-range-transported aerosols emitted during the 2020 Western US wildfires. This article is a prelude to the aerosol remote sensing that will be possible when a GEO-ring exclusively consisting of next generation imagers will be available with the launch of Meteosat Third Generation-Imager.