a. bracher, m. weber, k. bramstedt, m. v. könig, a. richter, a. rozanov, c. v. savigny,
DESCRIPTION
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. Overview - PowerPoint PPT PresentationTRANSCRIPT
Page 1Validation 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
Page 2Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
OverviewStatus of ValidationValidation results: SCIAMACHY: operational O3-columns with GOME
NO2-columns operational and retrieved by IUP with GOMEMIPAS: operational O3-profiles with HALOE and SAGEII
operational MIPAS H2O-profiles with HALOESCIAMACHY: O3-profiles retrieved by IUP with POAM III
NO2-profile retrieved by IUP with POAM IIIConcluding remarks
Results of the Bremen group on retrieving trace gases from uncalibrated level 0 (raw) limb and nadir level 1 SCIAMACHY data are still preliminaryFirst validation results of MIPAS and SCIAMACHY trace gas products are still preliminary
Page 3Validation 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 BremenTOMS: 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
Instrument Data product Geometry EnvisatInstrument
SAGEII(10/84)
O3 profilesNO2 profilesH2O profiles
occultation G,M,S*
HALOE(9/91)
O3 profilesNO2 profilesH2O profilesCH4 profiles
occultation G,M,S*
only M,SPOAM III
O3 profilesNO2 profiles
occultation only S-IUP
GOME(4/95)
O3 columnsNO2 columnsO3 profiles
nadir
TOMS(7/96)
O3 columns nadir
SABER(12/01)
O3 profilesH2O profiles
limb
ACE-FTS(12/02)
O3 profilesNO2 profilesH2O profilesCH4 profiles
occultation
(3/98)
S
Page 4Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
SCIAMACHY and GOME DOAS O3 and NO2 products
SCIAMACHY
Version 3.53 and 4.0 equivalent to GOME 2.4:US standard atmosphere for NO2 leads to un-derestimation of VCD under polluted conditions
O3 lv2-product: UV fit window 325-335 nm VIS fit window 425-450 nm
NO2 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 NO2 in thetropics through fitting of H2O and O4
O3 lv2-product: UV fit window 325-335 nm no VIS product
NO2 lv2-product: VIS fit window 425-450 nm
Soon version 3.0: TOMS V7.0 climatology forO3 and column-/latitude- classified AMF
Page 5Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
Comparison of SCIAMACHY O3 total columns (UV) with GOME
• All O3 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 O3 total column retrieval still very good despite degradation of scan mirror (~3%)
Page 6Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
Comparison of O3 total columns: (SCIA-GOME)/GOME
SCIAMACHY (3.53) ozone columns (UV) about –5 % to GOME (2.7)
Page 7Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
Comparison of O3 total columns
SCIAMACHY (3.53) O3 total columns show –5 % to GOME (2.7)
Page 8Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
SCIAMACHY 4.0: Calibration orbits 2509 and 2510 Comparison of O3 total columns
Bad pixels already filtered outRetrieval of O3 columns not better than 3.53
Page 9Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
Comparison of SCIAMACHY O3 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
Page 10Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
Comparison of SCIAMACHY NO2 total columns (VIS) with GOMECalibration orbits 2509 and 2510
version 4.0
IUP retrieval (A. Richter)
GOME 2.7
Page 11Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
Comparison of NO2 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
Page 12Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
Comparison of NO2 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
Page 13Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
Comparison of NO2 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)
Page 14Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
Comparison of MIPAS (4.53) O3 profiles with HALOE (v19)High latitudes Southern Hemisphere
8.5) 8.5)
Number density VMR
HALOE within 250 km of MIPASmeasurements during the same day
57 collocations for 17.9.-21.10.2002most at 60°S - 90°S (32), only 3 in the tropics
Page 15Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
Comparison of MIPAS (4.53) O3 profiles with HALOE (v19)Tropics
number density VMR.3) .3)
Accuracy of HALOE O3-Profiles: 30-60 km 6% 15-30 km 20%
Page 16Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
Comparison of MIPAS (4.53) O3 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
Page 17Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
Comparison of MIPAS (4.53) O3 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 O3-Profiles: 10-50 km 10%But, some bad profiles with altitude error due to recent processing problems
76 collocations for 17.9.-31.10.2002Most at 60°S-90°S(20),60°N-90°N(32)only 16 in mid-latitudes, 8 in tropics
Page 18Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
Comparison of MIPAS (4.53) H2O 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 H2O-Profiles: 30-50 km15% 10-30 km 25%
20 collocations for 17.9.-21.10.2002Most at 30°-60° (16), only 4 at 60°-90°
Page 19Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
10
20
30
40
50
0 1x1012 2x1012 3x1012 4x1012 5x1012 6x1012 7x1012
10 - 40 km O3 columns:
SCIAMACHY: 378 DUPOAM III: 384 DU
Total O3 column:
GOME: 459 DUTOMS: 456 DU
SCIAMACHY - POAM III coincidence on April 25, 2002
SCIA, Rozanov Lat: 56o-59o N, Long: 238o-253o, 18:30 UTC SCIA, Savigny Lat: 56o-59o N, Long: 238o-253o, 18:30 UTC POAM, Lat: 62o N, Long: 253o, 2:50 UTC
O3 density [cm -3]
Alti
tude
[km
]
Comparison of IUP-SCIAMACHY O3profiles with POAM IIIRozanov: Differential retrieval employing Chappuis bands
Savigny: 3 wavelength retrieval employing O3 Chappuis bands
Preliminary results!
d
dd
10-40 km O3 vertical column:SCIAMACHY: 378 DUPOAM III: 384 DU
Total O3 column:GOME: 459 DUTOMS: 456 DU
SCIAMACHY at 56-59°N,238-253° 25.4.2002 18:30 UTCPOAM at 62°N, 253° 25.4.2002 2:50 UTC
Page 20Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
Comparison of IUP-SCIAMACHY NO2 profiles with POAM III
NO2 was scaled to the POAM
measurement and used as input to simulate the diurnal variation of
the NO2 vertical profile backward
to SZA = 49 deg.(All model runs by M. von Koenig)
IUP retrieval byA. Rozanov Preliminary results!
Page 21Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
Concluding Remarks (1)
SCIAMACHY compared to GOME•total O3 columns (3.53 and 4.0) ~ - 5% •NO2 SCD (4.0) consistent offset•NO2 VCD (4.0) AMF problems –60%- 0%, but NO2 VCD (3.53) much worse
Update to equivalent of GOME 3.0 (better climatology for NO2 and O3, iterative AMF)Comparison of GOME NO2 data to ground based measurements
SCIAMACHY O3 and NO2 profiles compared to POAMIIIThese preliminary results give confidence that good profile data can be retrieved fromSCIAMACHY limb measurements
Page 22Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
MIPAS O3 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 O3 profiles look quite good, below 20 km improvements requiredcomparisons of MIPAS temperature to HALOE (NCEP) temperaturecomparisons to SAGEII must sort out bad SAGEII profiles (error bars)
MIPAS H2O profiles (4.53)•compared to HALOE 20-55 km +5 - +15 %
MIPAS H2O profiles look quite good, <20 km and > 55km improvements required
Concluding Remarks (2)
Page 23Validation 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