Abstract
Passive satellite observations play an important role in monitoring
global aerosol properties and helping quantify aerosol radiative forcing
in the climate system. The quality of aerosol retrievals from the
satellite platform relies on well-calibrated radiance measurements from
multiple spectral bands, and the availability of appropriate particle
optical models. Inaccurate scattering phase function assumptions can
introduce large retrieval errors. High-spatial resolution, dual-view
observations from the Advanced Baseline Imagers (ABI) on board the two
most recent Geostationary Operational Environmental Satellites (GOES),
East and West, provide a unique opportunity to better constrain the
aerosol phase function. Using dual GOES reflectance measurements for a
dust event in the Gulf of Mexico in 2019, we demonstrate how a
first-guess phase function can be reconstructed by considering the
variations in observed scattering angle throughout the day. Using the
reconstructed phase function, aerosol optical depth retrievals from the
two satellites are self-consistent and agree well with surface-based
optical depth estimates. We evaluate our methodology and reconstructed
phase function against independent retrievals made from low-Earth-orbit
multi-angle observations for a different dust event in 2020. Our new
aerosol optical depth retrievals have a root-mean-square-difference of
0.028 – 0.087. Furthermore, the retrievals between the two
geostationary satellites for this case agree within about 0.06±0.073, as
compared to larger discrepancies between the operational GOES products,
which do not employ the dual-view technique.