Optical properties in the UV and visible spectral region of organic acids relevant to tropospheric aerosols

[摘要] Refractive and absorption indices in the UV and visible region of selectedaqueous organic acids relevant to tropospheric aerosols are reported. Theacids investigated are the aliphatic dicarboxylic acids oxalic, malonic,tartronic, succinic and glutaric acid. In addition we report data forpyruvic, pinonic, benzoic and phthalic acid. To cover a wide range ofconditions we have investigated the aqueous organic acids at differentconcentrations spanning from highly diluted samples to concentrations closeto saturation. The density of the investigated samples is reported and aparameterisation of the absorption and refractive index that allows thecalculation of the optical constants of mixed aqueous organic acids atdifferent concentrations is presented. The single scattering albedo iscalculated for two size distributions using measured and a synthetic set ofoptical constants. The results show that tropospheric aerosols consisting ofonly these organic acids and water have a pure scattering effect.

[学科分类] 大气科学