Page 1Atmospheric Chemistry Validation of ENVISAT – ESRIN - 3-7 May 2004
SCIAMACHY CO, CH4, N2Oscientific data products
algorithms:WFM-DOAS v0.4 (UBremen)
&IMLM (SRON)
comparisons with GB(FT)IR measurements
Martine De MazièreBelgian Institute for Space Aeronomy
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H. Schrijver, I. AbenSRON, The Netherlands
M. Buchwitz, R. De Beek, & J. Notholt, T. Warneke
Institute of Environmental Physics, University of Bremen, GermanyT. Blumenstock, A. Griesfeller
Forschungszentrum Karlsruhe, IMK, GermanyE. Mahieu, P. Demoulin,, P. Duchatelet
Institut d'Astrophysique et de Géophysique, University of Liège, BelgiumJ. Mellqvist, A. Strandberg
Chalmers University of Technology, SwedenA. Schulz
Alfred Wegener Institute for Polar and Marine Research (AWI), GermanyR. Sussmann
Forschungszentrum Karlsruhe, IFU, GermanyH. Fast, R. L. Mittermeier & K. Strong
Meteorological Service of Canada (MSC) & University of Toronto, Canada S. Wood, D. Smale
National Institute for Water and Air Research (NIWA), New-ZealandD. Griffith, N. Jones
University of Wollongong, AustraliaC. Rinsland
NASA Langley Research Center, USAD.Ionov
University of St. Petersburg, Russia
Coworkers at BIRA-IASBContributing PI’s
M. De MazièreT. Coosemans
J. GranvilleP. GérardT. Jacobs
K. Janssens J.C. LambertC. Vigouroux
Page 3Atmospheric Chemistry Validation of ENVISAT – ESRIN - 3-7 May 2004
Correlative dataset
Arrival Heights
Lauder
Wollongong
Izaña
Jungfraujoch& Zugspitze
HarestuaKiruna
Ny Alesund
Egbert
Kitt Peak
Mauna Loa
St Petersburg
Zvenigorod
Obninsk
AO ID126
Station name Lat N Lon E
Alt asl (m)
Egbert 44.23 -79.78 251Ny Alesund 78.91 11.88 20Kiruna 67.84 20.41 419Harestua 60.22 10.75 580Zugspitze 47.5 11.1 2964Jungfraujoch 46.55 7.98 3580Toronto 43.7 -79.4 174Kitt Peak 31.9 -111.6 2090Izana 28.3 -16.48 2367Wollongong -34.4 150.9 30Lauder -45.05 169.7 370Arrival Heights -77.83 166.7 190
CO from cloud-free pixels
(∆CO < 60%)Ship Cruise (AWI- Uni Bremen) Jan 25 – Feb 9, 2003
5 days of overlapping data
Page 4Atmospheric Chemistry Validation of ENVISAT – ESRIN - 3-7 May 2004
T. Warneke et al.
Cruise Jan/Feb 2003
IUP Bremen
Black - Ship trackGreen - trajectories (850 hPa) Blue - closest WFM-DOAS-dataRed - fires (from MODIS)
High CO from biomass burning
Page 5Atmospheric Chemistry Validation of ENVISAT – ESRIN - 3-7 May 2004
Comparison caveats(FT)IR is the only GB technique to provide correlative total column data – but
number of GB measurements is limited - cf. need clear sky
Period of SCIA data not optimised for best overlap with GB data;Only retrievals for cloud-free pixels are sufficiently reliable
A number of intercomparisons must be interpreted with care
Comparisons between total column data at high altitude stations;⇓
adopted approach: to use altitude-normalised data which is a better compromise for CH4 and N2O than for CO
- still in mountainous regions, pixels do not represent uniform elevationOr
to compare ‘anomalies’ wrt an ensemble average (e.g., for CO at Zugspitze)
Comparisons at stations situated near the coast (e.g. Lauder) - cf colocated pixels may be over sea
Verify whether SCIA data are over sea or have a large retrieval error
Page 6Atmospheric Chemistry Validation of ENVISAT – ESRIN - 3-7 May 2004
Altitude issueexample CO at Jungfraujoch – GB FTIR versus SCIA WFM-DOAS
Not normalised for altitude 3580 m normalised for altitude
+ GB FTIRX SCIA O SCIA cloud-free
M. De Mazière et al.Next comparisons with GB FTIR network adopt altitude-normalised data
Page 7Atmospheric Chemistry Validation of ENVISAT – ESRIN - 3-7 May 2004
Retrieval error versus ‘albedo’IMLM / SRON WFM-DOAS / UBremen
Error_CO < 60%Error_N2O < 30%Error_CH4 < 7%
Error_CO < 9E17 molec/cm2Error_CH4 < 1E18molec/cm2
2.5%N2O
0.5%CH4
2.5%COPrecision of GB FTIR data Accuracy of GB FTIR
2.5 %N2O10 %CH47 %CO
2 - 3 %N2O1 - 3 %CH42 - 4 %CO
Page 8Atmospheric Chemistry Validation of ENVISAT – ESRIN - 3-7 May 2004
COCO
Page 9Atmospheric Chemistry Validation of ENVISAT – ESRIN - 3-7 May 2004
0.E+00
1.E+18
2.E+18
3.E+18
4.E+18
5.E+18
6.E+18
7.E+18
-60 -40 -20 0 20 40 60
latitude
CO
(mol
ecul
es/c
m2 )
SCIA seaSCIA landFTS ship
Cruise FTIR data
Conditions of comparisons with WFM-DOAS data:
Same day ; +/- 1.5°lat ; closest lon; cloud-free SCIA pixel ; error for CO over sea < 60%
T. Warneke et al.
0
1
2
3
4
5
6
7
8
9
10
30/06/02 20/07/02 09/08/02 29/08/02 18/09/02 08/10/02 28/10/02 17/11/02 07/12/02 27/12/02
CO
VC
D, 1
018 m
ol/c
m2
GB
SCIA scientific*
0
1
2
3
4
5
6
7
8
9
10
30/06/02 20/07/02 09/08/02 29/08/02 18/09/02 08/10/02 28/10/02 17/11/02 07/12/02 27/12/02
CO
VC
D, 1
018 m
ol/c
m2
GB
SCIA scientific*
0
1
2
3
4
5
6
7
8
9
10
30/06/02 20/07/02 09/08/02 29/08/02 18/09/02 08/10/02 28/10/02 17/11/02 07/12/02 27/12/02
CO
VC
D, 1
018 m
ol/c
m2
GB
SCIA scientific*− GB● SCIA
Russian grating spectrometer data
Conditions of comparisons with IMLM (SRON) data:w/i 12 hours; w/i 1000 km radius; all SCIA pixels D. Ionov et al.
Page 10Atmospheric Chemistry Validation of ENVISAT – ESRIN - 3-7 May 2004
CO at Zugspitze: GB FTIR versus SCIA – WFM-DOASin terms of ‘anomalies’
-7.00
-5.00
-3.00
-1.00
1.00
3.00
5.00
7.00
9.00
Dez. 02 Feb. 03 Apr. 03 Jul. 03 Sep. 03 Nov. 03
Date
Col
umn
anom
aly
Zugspitze FTIR: Anomaly of pressurecorrected CO columns, individualmeasurements, 20 min integration time
SCIA_WFMD_v0.4: CO/O2 columnsanomaly, individual pixels from 500-kmradius around Zugspitze; includes cloudcontaminated pixels (69 %)
SCIA_WFMD_v0.4: CO/O2 columnsanomaly, individual pixels from 500-kmradius around Zugspitze; cloud flaggedpixels removed
IMK-IFUGarmisch
Page 11Atmospheric Chemistry Validation of ENVISAT – ESRIN - 3-7 May 2004
Error bars: +/- 1 sigma
0.40
0.60
0.80
1.00
1.20
1.40
1.60
1.80
Dez. 02 Feb. 03 Apr. 03 Jul. 03 Sep. 03 Nov. 03 Feb. 04
Date
Col
umn
anom
aly
Zugspitze FTIR CO column anomaly: daily means
SCIA_WFMD_v0.4 CO/O2 column anomaly: average of allpixels within 500 km around Zugspitze for daily overpass;cloud falgged pixels removed
Polynomial 3rd order
Polynomial 3rd order
IMK-IFUGarmisch
Are observed variabilities consistent ?
Page 12Atmospheric Chemistry Validation of ENVISAT – ESRIN - 3-7 May 2004
CO globally – FTIR network versus WFM-DOAS
AO ID126 FTIR network
relative differences SCIA-FTIR (%)
Jan 2003 Nov 2003
Error_based selection
relative differences SCIA-FTIR (%)
AO ID126 FTIR network
Conditions of comparisons with SCIA data:
Open symbols:Same day; +/- 2.5°lat and +/- 10° lon; cloud-free SCIA pixel ;
Yellow filled symbols:Same day; +/- 2.5°lat and +/- 5° lon; cloud-free SCIA pixel ; altitude w/i +/- 250 m
altitude-normalised data
M. De Mazière et al.
Page 13Atmospheric Chemistry Validation of ENVISAT – ESRIN - 3-7 May 2004
CO globally – FTIR network versus IMLM
July 2002 Mid-April 2003
Error_based selection
relative differences SCIA-FTIR (%)
AO ID126 FTIR network
Conditions of comparisons with SCIA data: Open symbols:Same day; +/- 2.5°lat and +/- 10° lon; cloud-free SCIA pixel ;
Yellow filled symbols:Same day; +/- 2.5°lat and +/- 5° lon; cloud-free SCIA pixel ; altitude w/i +/- 250 m
altitude-normalised data
M. De Mazière et al.
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CHCH44
Page 15Atmospheric Chemistry Validation of ENVISAT – ESRIN - 3-7 May 2004
1000
1200
1400
1600
1800
2000
2200
2400
-60 -40 -20 0 20 40 60latitude
CH
4 (pp
bv)
SCIA seaSCIA landFTS shipNOAA/CMDL
Cruise FTIR data
Conditions of comparisons with WFM-DOAS data:
Same day ; +/- 1.5°lat ; closest lon; cloud-free SCIA pixel ; error for CH4 over sea < 7%T. Warneke et al.
CH4 cruise data scaled by 0.9 to agree with NOAA/CMDL data
Page 16Atmospheric Chemistry Validation of ENVISAT – ESRIN - 3-7 May 2004
CH4 globally – FTIR network versus WFM-DOAS
Jan 2003 Mid-Sept 2003
Error_based selection
relative differences SCIA-FTIR (%)AO ID126
FTIR network
Conditions of comparisons with SCIA data:
Open symbols:Same day; +/- 2.5°lat and +/- 10° lon; cloud-free SCIA pixel ;
Yellow filled symbols:Same day; +/- 2.5°lat and +/- 5° lon; cloud-free SCIA pixel ; altitude w/i +/- 250 m
altitude-normalised data
M. De Mazière et al.
Page 17Atmospheric Chemistry Validation of ENVISAT – ESRIN - 3-7 May 2004
CH4 globally – FTIR network versus IMLM
Mid-April 2003Jan 2003
Error_based selection
relative differences SCIA-FTIR (%)AO ID126
FTIR network
Conditions of comparisons with SCIA data:
Open symbols:Same day; +/- 2.5°lat and +/- 10° lon; cloud-free SCIA pixel ;
Yellow filled symbols:Same day; +/- 2.5°lat and +/- 5° lon; cloud-free SCIA pixel ; altitude w/i +/- 250 m
altitude-normalised data
M. De Mazière et al.
Page 18Atmospheric Chemistry Validation of ENVISAT – ESRIN - 3-7 May 2004
NN22OO
Page 19Atmospheric Chemistry Validation of ENVISAT – ESRIN - 3-7 May 2004
0.0E+00
3.0E+18
6.0E+18
9.0E+18
1.2E+19
1.5E+19
1.8E+19
-60 -40 -20 0 20 40 60latitude
N2O
(mol
ecul
es/c
m2 )
sealandFTIR
Cruise FTIR data
Conditions of comparisons with WFM-DOAS data:
Same day ; +/- 1.5°lat ; closest lon; cloud-free SCIA pixel ; error for N2O over sea< 30%T. Warneke et al.
Page 20Atmospheric Chemistry Validation of ENVISAT – ESRIN - 3-7 May 2004
N2O globally – FTIR network versus WFM-DOAS
Jan 2003 Mid-Sept 2003
Error_based selection
relative differences SCIA-FTIR (%)
AO ID126 FTIR network
Conditions of comparisons with SCIA data:
Open symbols:Same day; +/- 2.5°lat and +/- 10° lon; cloud-free SCIA pixel ;
Yellow filled symbols:Same day; +/- 2.5°lat and +/- 5° lon; cloud-free SCIA pixel ; altitude w/i +/- 250 m
altitude-normalised data
M. De Mazière et al.
Page 21Atmospheric Chemistry Validation of ENVISAT – ESRIN - 3-7 May 2004
Conclusions
Late availability of data has not allowed many nor detailed analyses
Conclusions from available limited (in number and depth) intercomparisons:
Scientific data products are a large improvement upon NRT products and demonstrate the capability of SCIAMACHY to detect variability in CO, CH4 and N2O
Actual performances of wfm-doas and IMLM algorithms are similar –Observed relative differences with GB data (SCIA-GB) are within
-50 → +50 % for CO – overestimation by WFM-DOAS? underestimation by IMLM ? TBC-40 → +40 % for CH4-20 → +60% for N2O (wfm-doas only)
Conservative estimates! Conditions for comparisons need improvement; more statistics are welcome
Page 22Atmospheric Chemistry Validation of ENVISAT – ESRIN - 3-7 May 2004
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