Optical properties in the UV and visible spectral region of organic acids relevant to tropospheric aerosols C. E. Lund Myhre and C. J. Nielsen Department of Chemistry, University of Oslo, P.O. Box 1033 Blindern, N-0372 Oslo, Norway
Abstract. Refractive and absorption indices in the UV and visible region of selected
aqueous organic acids relevant to tropospheric aerosols are reported. The
acids investigated are the aliphatic dicarboxylic acids oxalic, malonic,
tartronic, succinic and glutaric acid. In addition we report data for
pyruvic, pinonic, benzoic and phthalic acid. To cover a wide range of
conditions we have investigated the aqueous organic acids at different
concentrations spanning from highly diluted samples to concentrations close
to saturation. The density of the investigated samples is reported and a
parameterisation of the absorption and refractive index that allows the
calculation of the optical constants of mixed aqueous organic acids at
different concentrations is presented. The single scattering albedo is
calculated for two size distributions using measured and a synthetic set of
optical constants. The results show that tropospheric aerosols consisting of
only these organic acids and water have a pure scattering effect.
Citation: Lund Myhre, C. E. and Nielsen, C. J.: Optical properties in the UV and visible spectral region of organic acids relevant to tropospheric aerosols, Atmos. Chem. Phys., 4, 1759-1769, doi:10.5194/acp-4-1759-2004, 2004.