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SCIAMACHY Validation Workshop, 6-8 Dec 2004, Bremen
CO, CH4, CO2, and N2O columns retrieved from SCIAMACHY by WFM-DOAS: Algorithm, released data products, and initial
validation/verification
M. Buchwitz, R. de Beek, H. Bovensmann, J. P. Burrows (IUP/IFE-Bremen)
Data products released for validation
WFM-DOAS data products: Vertical columns of CO, CH4, CO2, and N2O; Dry air column averaged mixing ratios (O2 normalized columns) XCH4, XCO2, and XN2O
WFM-DOAS Version 0.4 finished in March 2004; processing of first large data set (~30 days of 2003); availability of first products announced on 17 March 2004
Initial validation results presented at 2nd ENVISAT Validation Workshop ACVE-2, May 2004, Frascati, ESA/ESRIN
-> Details see references on next slide
Processing of all consolidated orbits available for the year 2003; availability announced on 6 September 2004 (v0.4)
Improved methane (v0.41) announced on 30 September 2004
Analysis ongoing ...
Recent publications
Atmospheric Chemistry and Physics (ACP/ACPD):Buchwitz, M., R. de Beek, K. Bramstedt, S. Noël, H. Bovensmann, and J. P. Burrows, Global carbon monoxide as retrieved from SCIAMACHY by WFM-DOAS, ACP, 4, 1945-1960, 2004
Buchwitz, M., R. de Beek, J. P. Burrows, H. Bovensmann, T. Warneke, J. Notholt, J. F. Meirink, A. P. H. Goede, P. Bergamaschi, S. Körner, M. Heimann, J.-F. Muller, and A. Schulz, Atmospheric methane and carbon dioxide from SCIAMACHY satellite data: Initial comparison with chemistry and transport models , ACPD, 2004
Warneke, T., de Beek, R., Buchwitz, M., et al., O., Shipborne solar absorption measurements of CO2, CH4, N2O, and CO and comparison the SCIAMACHY WFM-DOAS retrievals, ACPD (submitted), 2004
Sussmann, R., and Buchwitz, M., Validation of ENVISAT/SCIAMACHY columnar CO by FTIR profile retrievals at the ground truthing station Zugspitze, ACPD (submitted), 2004
ENVISAT validation workshop ACVE-2 (May 2004, Frascati):de Maziere, M., Barret, B., Blumenstock, T., Buchwitz, M., de Beek, R., et al., Comparison between SCIAMACHY scientific products and ground-based FTIR data for total columns of CO, CH4, and N2O, proceedings ACVE-2 (ESA Special
Publication), ESA/ESRIN, Frascati, Italy, 3-7 May 2004, 2004
Gloudemans, A. M. S., Schrijver, H., Straume, A. G., Aben, I., Maurellis, A. N., Buchwitz, M., de Beek, R., et al., CH4 and CO
total columns from SCIAMACHY: Comparisons with TM3 and MOPITT, proceedings ACVE-2 (ESA Special Publication), ESA/ESRIN, Frascati, Italy, 3-7 May 2004, 2004
ENVISAT Symposium (Sept. 2004, Salzburg):Buchwitz, M., R. de Beek, S. Noël, H. Bovensmann, and J. P. Burrows, Retrieval of CO, H2O, CH4, CO2, ans N2O columns
from SCIAMACHY/ENVISAT by WFM-DOAS: Current status, ESA Special Publication SP-572, 2004.
WFM-DOAS algorithm
SCIAMACHY nadir spectrum & fitting windows
CH4, N2O CO
O2 CO2
Carbon monoxide from SCIAMACHY
Carbon monoxide (CO)
CO: Single overpass
Mozambique:
CO plumes from fires
Fires due to biomass burning in Africa Oct 2003
Buchwitz et al., ACP, 2004
CO: Single overpass II
Buchwitz et al., ACP, 2004
CO averaging kernels: SCIAMACHY and MOPITT
Emmons et al., JGR, 2004
MOPITTSCIAMACHY
Buchwitz et al., ACP, 2004
CO: Seasonal averages
CO: Monthly means compared with MOPITT
MOPITT data: H. Bremer, IUP-Bremen
CO: Monthly means compared with MOPITT II
ATSR Fire Atlas
Fires Portugal Aug 2003
MOPITT data: H. Bremer, IUP-Bremen
Methane from SCIAMACHY
Methane (CH4)
Methane v0.4: Comparison with models
Day 2003
IHD SCIA
[ppbv]
IHD model
[ppbv]
Mean difference
SCIA – model
[ppbv]
Standard
Deviation
[ppbv]
Jan 24 53 56 +10 (+0.6%) 97 (5.6%)
Mar 28 30 48 -186 (-10.6%) 89 (5.1%)
May 30 110 56 +48 (+2.7%) 200 (11.3%)
Jul 23 31 63 -266 (-15.1%) 122 (6.8%)
TM5 data: P. Bergamaschi, JRC, Ispra
Methane v0.4: Bias analysis/correction
Gives daily
correction factor
based on SOST
throughput
analysis
Methane v0.41
1st order bias corrected XCH4 monthly averages:
v0.4: XCH4=CH4col/(O2col/0.2095) v0.41: XCH4=XCH4v0.4/(XCO2v0.4/370)
Normalization by CO2, see also results from C. Frankenberg, IUP/Heidelberg
Error source CH4 column O2 column CO2 column CH4/O2 CH4/CO2
Aerosol(OD 0.0) -0,3 -2,5 -0,8 2,2 0,5Subvisual cirrus(OD 0.03) -3,7 2,8 -1,4 -6,5 -2,3
Albedo(0.3 instead of 0.1) 0,8 -3,0 1,4 3,8 -0,6
WFM-DOAS v0.4 retrieval
errors (in percent)
Buchwitz and Burrows,
SPIE, 2004
Methane v0.41: Comparison with KNMI/TM3 model
7%
Methane v0.41: Comparison with JRC/TM5 model
Courtesy: P. Bergamaschi, JRC, Ispra
Correlation SCIA/WFMD CH4 v0.41 with JRC/TM5
Bias [ppbv]
0%
~5%
Carbon dioxide from SCIAMACHY
Carbon dioxide (CO2)
CO2 v0.4: Comparison with TM3/MPI-BGC model
Buchwitz et al., ACPD, 2004 TM3 data: S. Körner, MPI-BGC, Jena
CO2 v0.4: Comparison with TM3 /MPI-BGC model II
Buchwitz et al., ACPD, 2004 TM3 data: S. Körner, MPI-BGC, Jena
CO2 v0.4: Comparison with TM3 /MPI-BGC model III
XCO2-offset MPI-Jena
8 ppm
25 ppm (7%)May 03
Jul 03
Sep 03
Summary
Horizontal
resolution
[km x km]
Estimated
Precision
(scatter)
Estimated
Accuracy
(bias)
CO 30 x 120 10 - 20% 10 - 30%
CH4 30 x 120 1- 6% 2 - 15%
(v0.41: <5%)
CO2 30 x 60 1 - 4% 2 - 5%
N2O 30 x 120 10 – 20% 30%
Preliminary precision and accuracy estimates *)
WFM-DOAS Version 0.4 column retrieval
*) Status ACVE-2 (May 2004)
For measurements over land; based on a limited number of data (several days of the year 2003)
Details see: Buchwitz et al., Envisat Sym., 2004, and references given therein
Acknowledgements
This work has been funded by:
• BMBF via GSF and DLR-Bonn,
• the European Commission (5th Framework project EVERGREEN)
• and the State and the University of Bremen