HR: 1340h
AN: A33D-0093    [Abstracts]
TI: Zenith-sky Total Ozone Column Retrievals in the Ultraviolet
AU: * Bojkov, B R
EM: bojan.bojkov@gsfc.nasa.gov
AF: Science Systems and Applications, Inc., 10210 Greenbelt Rd, Suite 600, Lanham, MD 20706 United States
AU: * Bojkov, B R
EM: bojan.bojkov@gsfc.nasa.gov
AF: NASA Goddard Space Flight Center, Code 916, Greenbelt, MD 20771 United States
AU: Bhartia, P K
EM: Pawan.K.Bhartia@nasa.gov
AF: NASA Goddard Space Flight Center, Code 916, Greenbelt, MD 20771 United States
AU: Hilsenrath, E
EM: Ernest.Hilsenrath@nasa.gov
AF: NASA Goddard Space Flight Center, Code 916, Greenbelt, MD 20771 United States
AB: A new algorithm to determine the total column ozone from zenith-sky intensities in the ultraviolet, ZTOZ, has been developed for the Shuttle Solar Backscatter Ultraviolet Spectrometer (SSBUV) instrument at the NASA Goddard Space Flight Center. The algorithm derives total ozone column amounts by comparing a ratio of measured intensities from three wavelengths with the equivalent intensity ratios calculated by radiative transfer. ZTOZ allows retrievals of total ozone at solar zenith angles larger than 70 degrees with far more accuracy than can be provided by conventional direct-sun measurements. This capability is important for validating satellite ozone measurements at high solar zenith angles and high latitudes where the direct-sun retrievals become increasingly less accurate. For the period beginning in October 2001, the differences between the ZTOZ and the collocated GSFC Brewer double monochromator direct-sun total column ozone measurements are within 2% and the precision is 1% or less. The ZTOZ methodology, as well as the influences of the ozone profiles, surface albedo, solar zenith angle, and aerosols on the accuracy of the retrieved total ozone amounts will be presented. The applicability of ZTOZ to existing Dobson and Brewer spectrometers operating in zenith-sky mode will also be discussed.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0394 Instruments and techniques
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting