Atmospheric Chemistry and Physics Discussions www.atmos-chem-phys-discuss.net 1680-7367 1680-7375 9 5 2009 10.5194/acpd-9-19009-2009 http://www.atmos-chem-phys-discuss.net/9/19009/2009/ http://www.atmos-chem-phys-discuss.net/9/19009/2009/acpd-9-19009-2009.html http://www.atmos-chem-phys-discuss.net/9/19009/2009/acpd-9-19009-2009.pdf 19009 19033 2009-09-14 Aerosol Single Scattering Albedo retrieval in the UV range: an application to OMI satellite validation I. Ialongo iolanda.ialongo@uniroma1.it V. Buchard C. Brogniez G. R. Casale A. M. Siani Physics Department, University of Rome, Sapienza, Italy Laboratoire d'Optique Atmosphérique (LOA), Université des Sciences et Technologies de Lille, France The aerosol Single Scattering Albedo (SSA) and Absorbing Aerosol Optical Depth (AAOD) at 320.1 nm are derived at Rome site by the comparison between Brewer and modelled spectra. The UVSPEC radiative transfer model is used to calculate the UV irradiances for different SSA values, taking into account as input data total ozone and Aerosol Optical Depth (AOD) obtained from Brewer spectral measurements. The accuracy in determining SSA depends on the aerosol amount and on Solar Zenith Angle (SZA) value: SSA uncertainty increases when AOD and SZA decrease. The monthly mean values of SSA and AAOD during the period January 2005–June 2008 are analysed, showing a monthly and seasonal variability. It is found that the SSA and AAOD averages are 0.80±0.08 and 0.056±0.028, respectively. AAOD retrievals are also used to quantify the error in the Ozone Monitoring Instrument (OMI) surface UV products due to absorbing aerosols, not included in the current OMI UV algorithm. OMI and Brewer UV irradiances at 324.1 nm and Erythemal Dose Rates (EDRs) under clear sky conditions, are compared as a function of AAOD. 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