Comparison of total ozone and erythemal UV data from OMI with ground-based measurements at Rome station

I. Ialongo (1) , G. R. Casale (1) , A. M. Siani (1)

1 Physics Department

Ground-based total ozone and surface UV irradiance measurements have been collected since 1992 using Brewer spectrophotometer and Erythemal Dose Rates (EDRs) have been determined by a broad-band radiometer (model YES UVB-1) operational since 2000 at Rome station. The methodology to retrieve the EDR and the Erythemal Daily Dose (EDD) from the radiometer observations is described. Ground-based measurements were compared with satellite-derived total ozone and UV data from the Ozone Monitoring Instrument (OMI). OMI, onboard the NASA EOS Aura spacecraft, is a nadir viewing spectrometer that provides total ozone and surface UV retrievals. The results of the validation exercise showed satisfactory agreement between OMI and Brewer total ozone data, for both OMI-TOMS and OMI-DOAS ozone alghorithms (biases of ?1.8% and ?0.7%, respectively). Regarding UV data, OMI data overestimate ground-based erythemally weighted data retrieved from both Brewer and YES Radiometer (biases about 20%), probably because of the effect of absorbing aerosols in an urban site such as Rome.

Domaines: Océan, Atmosphère

I. Ialongo, G. R. Casale, A. M. Siani. Comparison of total ozone and erythemal UV data from OMI with ground-based measurements at Rome station. Atmospheric Chemistry and Physics Discussions, 2008, 8 (1), pp.2381-2401. ⟨hal-00303963⟩