Retrieval of aerosol single scattering albedo at ultraviolet wavelengths at the T1 site during MILAGRO

We used the MFRSR data, together with measurements from a co-located CIMEL Sun photometer at the site operating as part of the AERONET network, to deduce aerosol single scattering albedo (ω) at 368 and 332 nm for four cloud-free days during the study.

Our retrievals suggest that T1 aerosols with aerosol extinction optical depth τ₃₆₈>0.1 that are influenced by Mexico City emissions, blowing dust, and biomass burning, are characterized by low ω₃₆₈=0.73-0.85 and ω₃₃₂=0.70-0.86, with small or no spectral variation of ω between 368 and 332 nm. Our findings are consistent with other published estimates of ω for Mexico City aerosols, including those that suggest that the absorption attributable to these aerosols is enhanced at UV wavelengths relative to visible wavelengths.