Institut für Umweltphysik/Fernerkundung Physik/Elektrotechnik Fachbereich 1 Astrid Bracher, M. Weber, K. Bramstedt,M. Coldewey-Egbers, L. N. Lamsal, John Burrows Institute of Environmental Physics (IUP/IFE), University of Bremen (part of it to be submitted to ACP special issue in December 2004) SCIAMACHY Validation Workshop, Bremen, Germany, 7 Dec 2003 Global satellite validation of SCIAMACHY O 3 and NO 2 columns with GOME WFDOAS/3.0

Institut für Umweltphysik/Fernerkundung Physik/Elektrotechnik Fachbereich 1 SCIAMACHY total O 3 validation with GOME WFDOAS All SCIAMACHY 5.01/5.04 from Jan - June 2003 compared to GOME WFDOAS V1.0 (to be submitted to ACP SCIAMACHY special issue II) SCIAMACHY reprocessed data of 2003 mixture of v5.01/5.04: only differences in processing settings, wrong season index in 5.01 for Jan-Mar 2003 equivalent to GOME GDP 2.4: no efficient temperature correction AMF calculations: -with ozone climatology based on 2 dim CTM -no iterations to match tO 3 a priori with meas. limited treatment of atmos. profile shape effect partly unsuitable spectral analysis when atmos- phere becomes optically thick. UV fit window nm GOME GDP 2.4 known for: strong dependencies to sza, tO3, seasons, latitude GOME WFDOAS by Coldewey-Egbers et al. (ACPD, 2004) Improved Raman correction ( to account for O 3 -depend. contribution to Ring effect) ozone temperature correction Cloud cover and effective scene height from oxygen A-band absorption (Koellemeijer et al. 2001) incl. ghost vertical column correction Effective UV albedo (surface reflect.) from 377nm Spectral fitting window: nm

Institut für Umweltphysik/Fernerkundung Physik/Elektrotechnik Fachbereich 1 Comparison of WFDOAS with groundbased data 56 stations Brewer/Dobson/SAOZ/M124 –mid-latitudes and tropics agreement to within 1% little seasonal variation (cosine amplitudes below 0.5% in general) –polar latitudes differences of up to +4 to +8% in winter (dependent on individual stations) –little seasonal variation (cosine amplitudes below 0.5% in general) SH Polar NH Polar mid-lat & tropics coincidence criteria: 300 km & same day from Weber et al., ACPD 2004 GOME WFD global validation with ground-based

Institut für Umweltphysik/Fernerkundung Physik/Elektrotechnik Fachbereich 1 SCIAMACHY total O 3 with GOME WFDOAS All O 3 data of one day (16 Apr 2003) in 2.5° latitudinal X 2.5° longitudinal grids, only SCIAMACHY data <90° SZA comparison of SCIAMACHY and GOME within the same grid GOME WFDOAS V1.0 SCIAMACHY v5.01

Institut für Umweltphysik/Fernerkundung Physik/Elektrotechnik Fachbereich 1 70°S-23°N –1.5% to –3% (+1-2%) 23°N-60°N –1.5% to +3% (+2-3%) (SCIAMACHY v5.01 -GOME-WFD)/GOME-WFD at 16 Apr 2004 SCIAMACHY total O 3 with GOME WFDOAS

Institut für Umweltphysik/Fernerkundung Physik/Elektrotechnik Fachbereich 1 tO 3 : (SCIA v5.01/5.04 -GOME WFD/GOME WFD) Polar Latitudes North South SCIAMACHY to GOME winter: –7.5 to +2.5% (+3-5%)summer: –1.5 to 0% (+2%) spring-summer: –1.5 to +4% (+3%)fall-winter: –3 to +1% (+2-4%) no. of bins < 300 strong increase in scatter of mean relative deviation and of RMS

Institut für Umweltphysik/Fernerkundung Physik/Elektrotechnik Fachbereich 1 Mid Latitudes North South SCIAMACHY to GOME winter: –2 to +3% (+2-3%)summer-fall: –2 to –0.5% (+1-1.5%) spring-summer: –2 to +1% (+1.5-2%)early winter:within 1% (+2-3%) tO 3 : (SCIA v5.01/5.04 -GOME WFD/GOME WFD)

Institut für Umweltphysik/Fernerkundung Physik/Elektrotechnik Fachbereich 1 TropicsGlobal SCIAMACHY to GOME –2.5 to –0.5% (+1%) –2 to +0.5% (+2%) tO 3 : (SCIA v5.01/5.04 -GOME WFD/GOME WFD)

Institut für Umweltphysik/Fernerkundung Physik/Elektrotechnik Fachbereich 1 comparison as a function of solar zenith angle (SZA) one day Jan to June 2003 SCIA to GOME mean relative deviation:20° to 60° increase of mean relative deviation with SZA, >60°to 85° decrease, >85° increase again RMS:>85° SZA RMS much higher than below no dependence to number of bins tO 3 : (SCIA v5.01/5.04 -GOME WFD/GOME WFD)

Institut für Umweltphysik/Fernerkundung Physik/Elektrotechnik Fachbereich 1 comparison as a function of total ozone one day Jan to June 2003 SCIAMACHY to GOME mean relative deviation: increase with total ozone to <390 DU >390 DU small decrease with total ozone RMS:dependence to no. of bins only for half year mean tO 3 : (SCIA v5.01/5.04 -GOME WFD/GOME WFD)

Institut für Umweltphysik/Fernerkundung Physik/Elektrotechnik Fachbereich 1 V4.0: V5.0-old: 70°S-80°N -60%–0% 70°S-80°N -60%–0% (+/-2-15%) (+/-2-15%) Verification orbits 2508 & Aug 2002 SCIAMACHY to GOME 3.0 Case1 from 5.0-verif.: 65°S-80°N -7%–15% (+/-2-15%) NO 2 VCD : (SCIAMACHY-GOME 3.0)/GOME W3.0 Status March 2004 no latitudinal dependence! % error 50 0 latitude latitude % error latitude

Institut für Umweltphysik/Fernerkundung Physik/Elektrotechnik Fachbereich 1 NO 2 VCD : (SCIAMACHY-GOME 3.0)/GOME 3.0 Daily comparisons as function of latitude from Jan-June 2003 v5.01/5.04 % error latitude 10 Jan v Mar v Jun v May v latitude % error

Institut für Umweltphysik/Fernerkundung Physik/Elektrotechnik Fachbereich 1 NO 2 SCD : (SCIAMACHY-GOME 3.0)/GOME W3.0 % error 10 Jan v Mar v latitude 12 May v5.01 Daily comparisons as function of latitude from Jan-June 2003 v5.01/ Jun v5.04 % error latitude

Institut für Umweltphysik/Fernerkundung Physik/Elektrotechnik Fachbereich 1 NO 2 VCD : (SCIAMACHY-GOME 3.0)/GOME W3.0 % error 20 Jun v sza 12 May v Jan v5.04 % error 2 Mar v5.04 % error sza Daily comparisons as function of solar zenith angle (SZA) from Jan-June 2003 v5.01/5.04 SH (solid) NH (light)

Institut für Umweltphysik/Fernerkundung Physik/Elektrotechnik Fachbereich 1 Summary: SCIAMACHY total ozone v5.01/5.04 Global validation with GOME WFDOAS V1 from Jan-June 2003 by fast binning method Slight underestimation of GOME WFDOAS (within +0.5 to –2%, RMS 2%), in accordance with ACVE-2 results Results improves when only SCIAMACHY data below 85° or even 75° SZA are used (Coupled) dependencies to seasons, latitudes and total ozone: increase of deviation from summer to winter as atmospheric variability increases detected in GOME GDP 2.4 (see Lambert et al., 2000) and attributed to: no temp. correction in O 3 cross sections, AMF calculations, atmospheric profile shape effect, spectral analysis when atmosphere optically thick, not including ozone filling-in as part of Ring effect Update to ~ GDP 4.0 or to WFDOAS of SCIAMACHY total ozone will probably lead to agreements within 1% with groundbased or GOME WFDOAS for SCIAMACHY data <85°!

Institut für Umweltphysik/Fernerkundung Physik/Elektrotechnik Fachbereich 1 Summary: SCIAMACHY total NO 2 v5.01/5.04 Global validation with GOME 3.0 from Jan-June 2003 by fast binning method Results show latitudinal dependence and in Winter-Spring in the Northern Hemisphere strong dependence to SZA! Results for SCIAMACHY 5.01/5.04 worse then for verification orbits v5.0 case 1 or case 4 (release 3/2004) and the results of ACVE-2!

Institut für Umweltphysik/Fernerkundung Physik/Elektrotechnik Fachbereich 1 ACKNOLEDGEMENTS DLR & ESA/ESRIN for GOME and SCIAMACHY lv 1 & lv 2 data For Funding: ESA-ESRIN (AO-project 651 SATVAL and contract 16402/02/I-LG) DLR-Bonn (contract No. 50 EE0025) BMBF (FKZ 01 SF9994, 7ATF42 (GOMSTRAT) within the AFO 2000) European Union (EU project EVK2-CT CANDIDOZ)

Institut für Umweltphysik/Fernerkundung Physik/Elektrotechnik Fachbereich 1 GOME WFDOAS & TOMS V8 Brewer DS GOME TOMS from Weber et al., ACPD 2004

Institut für Umweltphysik/Fernerkundung Physik/Elektrotechnik Fachbereich 1 GOME WFDOAS & TOMS V8 GOME TOMS Thanks to Bob Evans, NOAA from Weber et al., ACPD 2004