Atmospheric Chemistry and Physics Discussions www.atmos-chem-phys-discuss.net 1680-7367 1680-7375 4 5 2004 10.5194/acpd-4-6909-2004 http://www.atmos-chem-phys-discuss.net/4/6909/2004/ http://www.atmos-chem-phys-discuss.net/4/6909/2004/acpd-4-6909-2004.html http://www.atmos-chem-phys-discuss.net/4/6909/2004/acpd-4-6909-2004.pdf 6909 6941 2004-10-29 Pole-to-pole validation of GOME WFDOAS total ozone with groundbased data M. Weber weber@uni-bremen.de L. N. Lamsal M. Coldewey-Egbers K. Bramstedt J. P. Burrows Institute of Environmental Physics, University of Bremen, Bremen, Germany This paper summarises the validation of GOME total ozone retrieved using the weighting function differential optical absorption spectroscopy (WFDOAS) algorithm Version 1.0. This algorithm has been described in detail in a companion paper by Coldewey-Egbers et al. (2004). The WFDOAS results have been compared with selected ground-based measurements from the WOUDC (World Ozone and UV Radiation Data Centre) that collects total ozone measurements from a global network of stations covering all seasons. From the global validation excellent agreement between WFDOAS and ground data was found and on average agree to within ±1%. Very little seasonal variations in the observed differences are observed. In the polar region and at high solar zenith angles, however, a positive bias varying between 5 and 8% is found. Very few stations carry out simultaneous measurements by Brewer and Dobson spectrometers over an extended period (three years or more). Simultaneous Brewer and Dobson measurements from Hradec Kralove, Czech Republic (50.2° N, 15.8° E) and Hohenpeissenberg, Germany (47.8° N, 11.0° E) covering the period 1996–1999 have been compared with our GOME results. Agreement with Brewers are generally better than with the simultaneous Dobson measurements and this may be explained by the neglect of stratospheric (ozone) temperature correction in the standard ozone retrieval from the ground.