1. Page 1 Envisat Validation Workshop, ACVT-GBMCD, SCIAMACHY scient. prod. 12/12/2002 Envisat Validation Workshop Atmospheric Chemistry Validation Team Ground-Based Measurements and Campaign Database Subgroup Comparison of scientific SCIAMACHY products with ground-based measurements Klaus Bramstedt klaus.bramstedt@iup.physik.uni-bremen.de

2. Page 2 Envisat Validation Workshop, ACVT-GBMCD, SCIAMACHY scient. prod. 12/12/2002 Scientific products Non-operational algorithms for determining atmospheric parameters in the scientific community. Use:  Verification  Products not available yet  New products  Feedback for operat. products Limitations:  0-1 processing/calibration  availability of Level 1 products  "non-operational“  Only preliminary case studies Examples: - NO 2 col. - CH 4 /CO col. - Ozone profile (limb) – PMC detection

3. Page 3 Envisat Validation Workshop, ACVT-GBMCD, SCIAMACHY scient. prod. 12/12/2002 Scientific NO 2 columns  DOAS (ife, University of Bremen, A. Richter)  Pacific radiance used as reference spectrum in DOAS fit Compared with:  Groundb. DOAS  Ny Alesund  Bremen  Nairobi (AO 331, A. Richter)

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7. Page 7 Envisat Validation Workshop, ACVT-GBMCD, SCIAMACHY scient. prod. 12/12/2002 Comparison of CH 4 and CO  WFM-DOAS (M. Buchwitz, IUP/ife Bremen)  Reference spectra are derivatives of the radiance, fit parameter is VCD  Additional „Calibration Correction Function“ fitted  Iterat. maxim. likelihood method (H. Schrijver,SRON)  Modelled spectrum is fitted to the measured spectrum. Compared with:  FTIR  Ny-Alesund (AO 331, A. Schulz)  Kiruna (AO 191, T. Blumenstock)

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14. Page 14 Envisat Validation Workshop, ACVT-GBMCD, SCIAMACHY scient. prod. 12/12/2002 Comparison of O 3 profiles from limb  Limb ozone profiles (C. von Savigny, IUP/ife Bremen)  Normalized, paired limb radiances are analysed with an optimal estimation approach (OSIRIS) Compared with:  Ozone sondes from:  Ny-Alesund (AO 331, P. von der Gathen)  Neumayer (Antarctica) (AO 331, P. von der Gathen)  Hohenpeißenberg (AO 158, W. Steinbrecht)

15. Page 15 Envisat Validation Workshop, ACVT-GBMCD, SCIAMACHY scient. prod. 12/12/2002 Ny-Alesund 07.08.02Ny-Alesund 24.07.02

16. Page 16 Envisat Validation Workshop, ACVT-GBMCD, SCIAMACHY scient. prod. 12/12/2002 Neumayer 03.11.02Neumayer 10.10.02

17. Page 17 Envisat Validation Workshop, ACVT-GBMCD, SCIAMACHY scient. prod. 12/12/2002 Hohenpeißenberg 22.11.02Hohenpeißenberg 06.11.02

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19. Page 19 Envisat Validation Workshop, ACVT-GBMCD, SCIAMACHY scient. prod. 12/12/2002 Summary Preliminary Comparisons:  CH 4 /CO columns: 2 algorithms available  up to 50% dev. (same order of magnitude!!)  Ozone Limb profiles: Altitude shift (pointing problem?)  NO 2 columns: reliable relative and absolute values  Antarctic ozone hole identified!  PMCs can be detected in limb All scientific retrievals and their validation suffer from O-1 processing problems (calibration and availability), but: It´s in there!