Column ozone and aerosol optical properties retrieved from direct solar irradiance measurements during SOLVE II W. H. Swartz1, J.-H. Yee1, R. E. Shetter2, S. R. Hall2, B. L. Lefer2,*, J. M. Livingston3, P. B. Russell4, E. V. Browell5, and M. A. Avery5 1The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, USA 2National Center for Atmospheric Research, Boulder, Colorado, USA 3SRI International, Menlo Park, California, USA 4NASA Ames Research Center, Moffett Field, California, USA 5NASA Langley Research Center, Hampton, Virginia, USA *now at: University of Houston, Department of Geosciences, Houston, Texas, USA
Abstract. 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.
Citation: Swartz, W. H., Yee, J.-H., Shetter, R. E., Hall, S. R., Lefer, B. L., Livingston, J. M., Russell, P. B., Browell, E. V., and Avery, M. A.: Column ozone and aerosol optical properties retrieved from direct solar irradiance measurements during SOLVE II, Atmos. Chem. Phys., 5, 611-622, doi:10.5194/acp-5-611-2005, 2005.