HR: 1340h
AN: A33D-0092    [Abstracts]
TI: A Comparison of TOMS & SBUV Version 8 Total Column Ozone Data With Data From Groundstations
AU: * Labow, G J
EM: labow@qhearts.gsfc.nasa.gov
AF: SSAI & NASA GSFC, Goddard Space Flight Center Mail Code 916, Greenbelt, Md 20771
AU: Haffner, D P
EM: david_haffner@sesda.com
AF: SSAI & NASA GSFC, Goddard Space Flight Center Mail Code 916, Greenbelt, Md 20771
AU: McPeters, R D
EM: mcpeters@wrabbit.gsfc.nasa.gov
AF: NASA- Goddard Space Flight Center, Goddard Space Flight Center Mail Code 916, Greenbelt, Md 20771
AU: Bhartia, P
EM: bhartia@carioca.gsfc.nasa.gov
AF: NASA- Goddard Space Flight Center, Goddard Space Flight Center Mail Code 916, Greenbelt, Md 20771
AB: Data from the Nimbus-7 and Earth Probe Total Ozone Mapping Spectrometer (TOMS) as well as the Solar Backscatter UltraViolet (SBUV) series of instruments have been reprocessed with a new retrieval algorithm (Version 8), and an updated calibration procedure. These data have been systematically compared to total ozone data from Brewer and Dobson spectrophotometers for many individual ground stations. The comparisons were made as a function of latitude, solar zenith angle, reflectivity and total ozone. Results show that the accuracy of the TOMS retrieval is much improved when aerosols are present in the atmosphere, when snow/ice and sea glint are present, and when ozone in the northern hemisphere is extremely low. The SBUV total ozone values have now been calculated as the sum of the profile values instead of the pair method as in the previous version(s). Comparisons of the column measurements to the ozone measurements from the ground will be shown. TOMS overpass data are derived from the single TOMS best match measurement, almost always located within one degree of the ground station and usually made within an hour of local noon. Nimbus-7 and early EarthProbe TOMS data are well calibrated, however significant changes in the sensitivity of the EarthProbe instrument since 2000 have increased uncertainties in the data despite efforts to minimize them with special calibration methods. The agreement with groundstations are still very good but the data should not be used for trend studies. The SBUV measurements have been interpolated along the orbital track and distance weighted from the groundstation location. The time of the SBUV measurements vary according to the satellite's orbit and some do change significantly over a decadal time scale. Large station-to-station differences suggest the possibility of significant instrument errors at some ground stations.
DE: 1640 Remote sensing
DE: 0394 Instruments and techniques
DE: 0399 General or miscellaneous
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting