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Page 1 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002 Validation of ENVISAT trace gas data products by comparison.

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Presentation on theme: "Page 1 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002 Validation of ENVISAT trace gas data products by comparison."— Presentation transcript:

1 Page 1 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002 Validation of ENVISAT trace gas data products by comparison with GOME/ERS-2 and other satellite sensors A. Bracher, M. Weber, K. Bramstedt, M. v. König, A. Richter, A. Rozanov, C. v. Savigny, J. P. Burrows Institute of Environmental Physics, University of Bremen

2 Page 2 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002 Overview  Status of Validation  Validation results: SCIAMACHY: operational O 3 -columns with GOME NO 2 -columns operational and retrieved by IUP with GOME MIPAS:operational O 3- profiles with HALOE and SAGEII operational MIPAS H 2 O-profiles with HALOE SCIAMACHY: O 3- profiles retrieved by IUP with POAM III NO 2- profile retrieved by IUP with POAM III  Concluding remarks Results of the Bremen group on retrieving trace gases from uncalibrated level 0 (raw) limb and nadir level 1 SCIAMACHY data are still preliminary First validation results of MIPAS and SCIAMACHY trace gas products are still preliminary

3 Page 3 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002 Satellite Instruments for Validation of GOMOS,MIPAS & SCIAMACHY Cooperations: SAGE II : L. Thomason (NASA LaRC) HALOE, SABER: J.M. Russell III, E. Thompson (Hampton Univ.) POAM III: R. Bevilacqua (ONR, CNES, NRL) GOME: IUP Bremen TOMS: E. Hilsenrath, R. Mc Peters (NASA GSFC) ACE-FTS: P. Bernath, K. Walker (Univ. of Waterloo) green: first validation * = only SCIA profiles retrieved by IUP blue: new instruments InstrumentData productGeometryEnvisat Instrument SAGEII (10/84) O 3 profiles NO 2 profiles H 2 O profiles occultationG,M,S* HALOE (9/91) O 3 profiles NO 2 profiles H 2 O profiles CH 4 profiles occultationG,M,S* only M,S POAM III O 3 profiles NO 2 profiles occultationonly S-IUP GOME (4/95) O 3 columns NO 2 columns O 3 profiles nadir TOMS (7/96) O 3 columnsnadir SABER (12/01) O 3 profiles H 2 O profiles limb ACE-FTS (12/02) O 3 profiles NO 2 profiles H 2 O profiles CH 4 profiles occultation (3/98) S

4 Page 4 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002 SCIAMACHY and GOME DOAS O 3 and NO 2 products SCIAMACHY Version 3.53 and 4.0 equivalent to GOME 2.4: US standard atmosphere for NO 2 leads to un- derestimation of VCD under polluted conditions O 3 lv2-product:UV fit window 325-335 nm VIS fit window 425-450 nm NO 2 lv2-product:VIS fit window 425-450 nm Lv-1 product for 4.0 better than 3.53: new SCIAMACHY sun spectrum polarisation correction different spectral calibration different dark current GOME Version 2.7 with improvements for NO 2 in the tropics through fitting of H 2 O and O 4 O 3 lv2-product:UV fit window 325-335 nm no VIS product NO 2 lv2-product:VIS fit window 425-450 nm Soon version 3.0: TOMS V7.0 climatology for O 3 and column-/latitude- classified AMF

5 Page 5 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002 Comparison of SCIAMACHY O 3 total columns (UV) with GOME All O 3 data of time period in 2.5° X 2.5° grids Bad SCIA pixels (low/no light) filtered out Comparison of SCIAMACHY (3.53) and GOME (2.7) data within the same grid GOME O 3 total column retrieval still very good despite degradation of scan mirror (~3%)

6 Page 6 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002 Comparison of O 3 total columns: (SCIA-GOME)/GOME SCIAMACHY (3.53) ozone columns (UV) about –5 % to GOME (2.7)

7 Page 7 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002 Comparison of O 3 total columns SCIAMACHY (3.53) O 3 total columns show –5 % to GOME (2.7)

8 Page 8 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002 SCIAMACHY 4.0: Calibration orbits 2509 and 2510 Comparison of O 3 total columns Bad pixels already filtered out Retrieval of O 3 columns not better than 3.53

9 Page 9 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002 Comparison of SCIAMACHY O 3 total columns (VIS) with GOME (UV) SCIAMACHY (3.53) SCIAMACHY (4.0) SCIAMACHY 3.53 very bad (up to 200% difference to GOME) SCIAMACHY 4.0 much better, but still very big scatter

10 Page 10 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002 Comparison of SCIAMACHY NO 2 total columns (VIS) with GOME Calibration orbits 2509 and 2510 version 4.0 IUP retrieval (A. Richter) GOME 2.7

11 Page 11 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002 Comparison of NO 2 total columns: (SCIA-GOME)/GOME version 4.0 IUP retrieval (A. Richter) stable offset of –20%, <-60° down to –40% strong variation with latitude: –60% at 70°S to 0% at 70°N

12 Page 12 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002 Comparison of NO 2 slant columns: (SCIA-GOME)/GOME both retrievals show offset of –10% with strong scatter for SCIAMACHY largest contribution to total column error of operational product from AMF IUP retrieval (A. Richter) version 4.0

13 Page 13 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002 Comparison of NO 2 total columns: (SCIA-GOME)/GOME much worse than version 4.0 (there in lv1 data: better polarisation correction, sun spectrum) strong variation with latitude: –50% at 70°S to +140% at 70°N variation from 0% at high latitudes to +50% in the tropics no sun spectrum used, fitted against SCIA spectrum in the tropical Pacific version 3.53 IUP retrieval (A. Richter)

14 Page 14 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002 Comparison of MIPAS (4.53) O 3 profiles with HALOE (v19) High latitudes Southern Hemisphere 8.5 ) Number density VMR HALOE within 250 km of MIPAS measurements during the same day 57 collocations for 17.9.-21.10.2002 most at 60°S - 90°S (32), only 3 in the tropics

15 Page 15 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002 Comparison of MIPAS (4.53) O 3 profiles with HALOE (v19) Tropics number density VMR.3 ) Accuracy of HALOE O 3 -Profiles: 30-60 km 6% 15-30 km 20%

16 Page 16 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002 Comparison of MIPAS (4.53) O 3 profiles with HALOE (v19) Mean deviation for 20-60 km: MIPAS +10% – -15 % compared to HALOE (number density) +20% – -10%(VMR) 13-20 km: MIPAS large deviation to HALOE

17 Page 17 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002 Comparison of MIPAS (4.53) O 3 profiles with SAGEII (6.1) Mean deviation for 20-35 km: MIPAS +0% – -20 % compared to SAGEII (number density) +20% – -20%(VMR) 35-60 km:- 35% – -10% (number density & VMR) 13-20 km: MIPAS large deviation to SAGEII Accuracy of SAGEII O 3 -Profiles: 10-50 km 10% But, some bad profiles with altitude error due to recent processing problems 76 collocations for 17.9.-31.10.2002 Most at 60°S-90°S(20),60°N-90°N(32) only 16 in mid-latitudes, 8 in tropics

18 Page 18 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002 Comparison of MIPAS (4.53) H 2 O profiles with HALOE (v19) Mean deviation for >20-55 km: MIPAS +5% – +15 % compared to HALOE (VMR) 13-20 km: MIPAS large deviation to HALOE Accuracy of HALOE H 2 O-Profiles: 30-50 km15% 10-30 km 25% 20 collocations for 17.9.-21.10.2002 Most at 30°-60° (16), only 4 at 60°-90°

19 Page 19 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002 Comparison of IUP-SCIAMACHY O 3 profiles with POAM III Rozanov: Differential retrieval employing Chappuis bands Savigny: 3 wavelength retrieval employing O 3 Chappuis bands Preliminary results! d d d 10-40 km O 3 vertical column: SCIAMACHY: 378 DU POAM III: 384 DU Total O 3 column: GOME:459 DU TOMS:456 DU SCIAMACHY at 56-59°N,238-253° 25.4.2002 18:30 UTC POAM at 62°N, 253° 25.4.2002 2:50 UTC

20 Page 20 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002 Comparison of IUP-SCIAMACHY NO 2 profiles with POAM III NO 2 was scaled to the POAM measurement and used as input to simulate the diurnal variation of the NO 2 vertical profile backward to SZA = 49 deg. (All model runs by M. von Koenig) IUP retrieval by A. Rozanov Preliminary results!

21 Page 21 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002 Concluding Remarks (1) SCIAMACHY compared to GOME total O 3 columns (3.53 and 4.0) ~ - 5% NO 2 SCD (4.0) consistent offset NO 2 VCD (4.0) AMF problems –60%- 0%, but NO2 VCD (3.53) much worse Update to equivalent of GOME 3.0 (better climatology for NO 2 and O 3, iterative AMF) Comparison of GOME NO 2 data to ground based measurements SCIAMACHY O 3 and NO 2 profiles compared to POAMIII These preliminary results give confidence that good profile data can be retrieved from SCIAMACHY limb measurements

22 Page 22 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002 MIPAS O 3 profiles (4.53) compared to HALOE 20-60 km +/- 10 % for number dens., slight pos. bias for VMR compared to SAGEII 20-60 km –35 - 0% for number dens., slight pos. bias for VMR MIPAS O 3 profiles look quite good, below 20 km improvements required comparisons of MIPAS temperature to HALOE (NCEP) temperature comparisons to SAGEII must sort out bad SAGEII profiles (error bars) MIPAS H 2 O profiles (4.53) compared to HALOE 20-55 km +5 - +15 % MIPAS H 2 O profiles look quite good, 55km improvements required Concluding Remarks (2)

23 Page 23 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002 data quality of operational GOME NO2 not to good, data quality of GOME NO2 retrieved by the IUP (A. Richter) much better


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