190 likes | 329 Vues
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.
E N D
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
Non-operational algorithms for determining atmospheric parameters in the scientific community. Scientific products 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: - NO2 col. - CH4/CO col. - Ozone profile (limb) – PMC detection
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) Scientific NO2 columns
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) Comparison of CH4 and CO
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) Comparison of O3 profiles from limb
Ny-Alesund 24.07.02 Ny-Alesund 07.08.02
Neumayer 10.10.02 Neumayer 03.11.02
Hohenpeißenberg 06.11.02 Hohenpeißenberg 22.11.02
Preliminary Comparisons: CH4/CO columns: 2 algorithms available up to 50% dev. (same order of magnitude!!) Ozone Limb profiles: Altitude shift (pointing problem?) NO2 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: Summary It´s in there!