Is there a bias in AERONET retrievals of aerosol light absorption at low AOD conditions?
Other literature type
(issn: 1680-7324, eissn: 1680-7324)
Here we present new results comparing aerosol absorption optical depth (AAOD) and column single scattering albedo (SSA) obtained from in-situ vertical profile measurements with AERONET ground-based remote sensing from two rural continental sites in the US. The profiles are closely matched in time (within +/-3 h) and space (within 15 km) with the AERONET retrievals. These direct comparisons of in-situ-derived to AERONET-retrieved AAOD (or SSA) reveal that AERONET retrievals yield higher aerosol absorption for the low aerosol optical depth (AOD) conditions prevalent at the two study sites. The tendency of AERONET inversions to overestimate absorption at low AOD values is generally consistent with other published comparisons. We conclude that scaling modelled black carbon concentrations upwards to match AERONET retrievals of AAOD may lead to aerosol absorption overestimates in regions of low AOD.