Aerosol Optical Depth Retrievals over Land using the GOES-8/Imager Visible Channel

The retrieval of aerosol properties from satellite is a growing field, primarily because of (a) the recognition that aerosols can significantly affect the Earth's radiative budget and hence climate and (b) interest in regional aerosol sources and transport. Satellite aerosol retrievals can provide an estimate of their global distribution at a resolution impossible for ground-based sensors. However, the majority of sensors used in aerosol retrievals currently operating - as well as those proposed to be launched - are aboard polar orbiting satellites, which have low temporal coverage. With the recent efforts to calibrate the visible imagery from GOES-8, aerosol studies are possible from GOES-8 imagery.

Aerosol optical depth retrievals from GOES-8 have been performed and validated using surface observations of aerosol optical depth from the Aerosol Robotic Network (AERONET) of sun photometers. First, comparisons were made during the Smoke Cloud and Radiation - Brazil (SCAR-B) Experiment, where the primary aerosol source is biomass burning. Biomass burning aerosols with optical depths greater than 2 were observed from the network and GOES-8. Results showed a strong correlation between satellite retrieval and surface observation (r=0.9), yet a bias was evident, possibly due to aerosol optical property errors Further retrievals will be made over the United Stated where optical depths are lower and the aerosol has a more varied composition.