Initial validation of ENVISAT/SCIAMACHY columnar CO by FTIR profile retrievals at the Ground-Truthing Station Zugspitze R. Sussmann1 and M. Buchwitz2 1IMK-IFU, Forschungszentrum Karlsruhe, Garmisch-Partenkirchen, Germany 2Institute of Environmental Physics (iup), University of Bremen, Bremen, Germany
Abstract. Carbon monoxide vertical profile retrievals from ground-based solar FTIR
measurements at the Permanent Ground-Truthing Station Zugspitze (47.42° N,
10.98° E, 2964m a.s.l.), Germany are used to validate columnar CO
retrieved from ENVISAT/SCIAMACHY spectra (WFM-DOAS version 0.4). The
WFM-DOAS retrievals of CO include an empirical column scaling factor of 0.5.
Therefore, not absolute column levels are validated, but the proper response
of the SCIAMACHY retrievals to the atmospheric inter-annual variability is
quantitatively assessed in comparison to the Zugspitze FTIR results.
Although CO WFM-DOAS data for only 33 days were available for this
covering January-October 2003), it is possible to retrieve information on the CO
annual cycle (≈10% amplitude) in a statistically significant
fit out of the scatter of the SCIAMACHY WFM-DOAS data. To obtain this, all
pixels within a minimum radius of 2000km around Zugspitze had to be
averaged for each day.
Citation: Sussmann, R. and Buchwitz, M.: Initial validation of ENVISAT/SCIAMACHY columnar CO by FTIR profile retrievals at the Ground-Truthing Station Zugspitze, Atmos. Chem. Phys., 5, 1497-1503, doi:10.5194/acp-5-1497-2005, 2005.