Column ozone and aerosol optical properties retrieved from direct solar irradiance measurements during SOLVE II

W. H. Swartz (1) , J.-H. Yee (1) , R. E. Shetter (2) , S. R. Hall (2) , B. L. Lefer (2) , J. M. Livingston (3) , P. B. Russell (4) , E. V. Browell (5) , M. A. Avery (5)

1 APL - Johns Hopkins University Applied Physics Laboratory [Laurel, MD]
2 NCAR - National Center for Atmospheric Research [Boulder]
3 SRI - SRI International [Menlo Park]
4 ARC - NASA Ames Research Center
5 NASA Headquarters

Direct observation of the Sun at large solar zenith angles during the second SAGE III Ozone Loss and Validation Experiment (SOLVE II)/Validation of International Satellites and study of Ozone Loss (VINTERSOL) campaign by several instruments provided a rich dataset for the retrieval and analysis of line-of-sight column composition, intercomparison, and measurement validation. A flexible, multi-species spectral fitting technique is presented and applied to spectral solar irradiance measurements made by the NCAR Direct beam Irradiance Atmospheric Spectrometer (DIAS) on-board the NASA DC-8. The approach allows for the independent retrieval of O₃, O₂·O₂, and aerosol optical properties, by constraining Rayleigh extinction. We examine the 19 January 2003 and 6 February 2003 flights and find very good agreement of O₃ and O₂·O₂ retrievals with forward-modeling calculations, even at large solar zenith angles, where refraction is important. Intercomparisons of retrieved ozone and aerosol optical thickness with results from the Ames Airborne Tracking Sunphotometer (AATS-14) are summarized.

Domaines: Océan, Atmosphère

W. H. Swartz, J.-H. Yee, R. E. Shetter, S. R. Hall, B. L. Lefer, et al.. Column ozone and aerosol optical properties retrieved from direct solar irradiance measurements during SOLVE II. Atmospheric Chemistry and Physics Discussions, 2004, 4 (6), pp.7403-7431. ⟨hal-00301500⟩