Atmospheric Chemistry and Physics Discussions www.atmos-chem-phys-discuss.net 1680-7367 1680-7375 5 3 2005 10.5194/acpd-5-2677-2005 http://www.atmos-chem-phys-discuss.net/5/2677/2005/ http://www.atmos-chem-phys-discuss.net/5/2677/2005/acpd-5-2677-2005.html http://www.atmos-chem-phys-discuss.net/5/2677/2005/acpd-5-2677-2005.pdf 2677 2717 2005-05-03 Comparisons between SCIAMACHY and ground-based FTIR data for total columns of CO, CH₄, CO₂ and N₂O B. Dils M. De Mazière T. Blumenstock M. Buchwitz R. de Beek P. Demoulin P. Duchatelet H. Fast C. Frankenberg A. Gloudemans D. Griffith N. Jones T. Kerzenmacher I. Kramer E. Mahieu J. Mellqvist R. L. Mittermeier J. Notholt C. P. Rinsland H. Schrijver D. Smale A. Strandberg A. G. Straume W. Stremme K. Strong R. Sussmann J. Taylor M. van den Broek T. Wagner T. Warneke A. Wiacek S. Wood Belgian Institute for Space Aeronomy, Brussels, Belgium Forschungszentrum Karlsruhe, IMK-ASF, Karlsruhe, Germany Meteorological Service of Canada (MSC), Downsview, Ontario, Canada University of Wollongong, New South Wales, Australia Institut d’Astrophysique et de Gèophysique, Liège, Belgium Chalmers University of Technology, Radio & Space Science, Göteborg, Sweden Institute of Environmental Physics, University of Heidelberg, Heidelberg, Germany Institute of Environmental Physics, University of Heidelberg, Heidelberg, Germany Forschungszentrum Karlsruhe, IFU, Germany University of Toronto, Canada Institute of Environmental Physics, University of Bremen, FB1, Germany Netherlands Institute for Space Research (SRON), Utrecht, The Netherlands NASA Langley Research Center, Hampton, VA, USA Total column amounts of CO, CH₄, CO₂ and N₂O retrieved from SCIAMACHY nadir observations in its near-infrared channels have been compared to data from a ground-based quasi-global network of Fourier-transform infrared (FTIR) spectrometers. The SCIAMACHY data considered here have been produced by three different retrieval algorithms, WFM-DOAS (version 0.4, 0.41 for CH₄), IMAP-DOAS (version 0.9) and IMLM (version 5.5) and cover the January to December 2003 time period. Comparisons have been made for individual data, as well as for monthly averages. To maximize the number of reliable coincidences that satisfy the temporal and spatial collocation criteria, the SCIAMACHY data have been compared with a temporal 3rd order polynomial interpolation of the ground-based data. Particular attention has been given to the question whether SCIAMACHY observes correctly the seasonal and latitudinal variability of the target species. The ensemble of comparisons, discussed in this paper, demonstrate the capability of SCIAMACHY, using any of the three algorithms, to deliver products for the target species under consideration, which are already useful for qualitative geophysical studies on a global scale. It is expected that the remaining uncertainties in the data products will decrease in future versions of the algorithm to also allow more quantitative investigations on a regional scale.