Comparisons between SCIAMACHY and ground-based FTIR data for total columns of CO, CH4, CO2 and N2O
1Belgian Institute for Space Aeronomy, Brussels, Belgium
2Forschungszentrum Karlsruhe and University Karlsruhe, IMK-ASF, Karlsruhe, Germany
3Environment Canada, Downsview, Ontario, Canada
4University of Wollongong, New South Wales, Australia
5Institut d’Astrophysique et de Géophysique, Liège, Belgium
6Chalmers University of Technology, Radio & Space Science, Göteborg, Sweden
7Institute of Environmental Physics, University of Heidelberg, Heidelberg, Germany
8National Institute for Water and Air Research (NIWA), New Zealand
9Forschungszentrum Karlsruhe, IMK-IFU, Garmisch-Partenkirchen, Germany
10Department of Physics, University of Toronto, Toronto, Ontario, Canada
11Institute of Environmental Physics, University of Bremen, FB1, Germany
12Netherlands Institute for Space Research (SRON), Utrecht, The Netherlands
13NASA Langley Research Center, Hampton, VA, USA
Abstract. 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 0.5 for CO and CH4 and version 0.4 for CO2 and N2O), IMAP-DOAS (version 1.1 and 0.9 (for CO)) and IMLM (version 6.3) 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 present results indicate that the individual SCIAMACHY data obtained with the actual versions of the algorithms have been significantly improved, but that the quality requirements, for estimating emissions on regional scales, are not yet met. Nevertheless, possible directions for further algorithm upgrades have been identified which should result in more reliable data products in a near future.
Dils, B., De Mazière, M., Müller, J. F., Blumenstock, T., Buchwitz, M., de Beek, R., Demoulin, P., Duchatelet, P., Fast, H., Frankenberg, C., Gloudemans, A., Griffith, D., Jones, N., Kerzenmacher, T., Kramer, I., Mahieu, E., Mellqvist, J., Mittermeier, R. L., Notholt, J., Rinsland, C. P., Schrijver, H., Smale, D., Strandberg, A., Straume, A. G., Stremme, W., Strong, K., Sussmann, R., Taylor, J., van den Broek, M., Velazco, V., Wagner, T., Warneke, T., Wiacek, A., and Wood, S.: Comparisons between SCIAMACHY and ground-based FTIR data for total columns of CO, CH4, CO2 and N2O, Atmos. Chem. Phys., 6, 1953-1976, doi:10.5194/acp-6-1953-2006, 2006.