1. Comparison of other Sciamachy operational products
Envisat Validation Workshop
Atmospheric Chemistry Validation Team
Ground-Based Measurements and Campaign Database Subgroup
Comparison of other Sciamachy operational products
Renske Timmermans,

2. Contributions from AOID 427 – Yuri Timofeyev (PI), Dmitry Ionov
St. Petersburg State University
AOID 126 – Martine de Maziere (PI), Thierry Coosemans
BIRA-IASB
AOID 174 – Hennie Kelder (PI), Renske Timmermans,
Jan-Fokke Meirink, Ankie Piters
KNMI
Bogumil Kois
Legionowo, Poland

3. Intercomparison of CO columns
Direct solar observations with
IR spectrometer
Intercomparison of CO columns
CO columns
The nearest SCIAMACHY pixel is selected within a 500 km range from the GB station
Constant values found

4. CO columns

5. Intercomparison of CH4 columns
Direct solar observations with
IR spectrometer
Intercomparison of CH4 columns
The nearest SCIAMACHY pixel is selected within a 500 km range from the GB station
Constant values found

6. CH4 columns

7. CH4 columns
BIAS_1_CH4 22 nov
Constant value

8. Version 3.53, 25 October-10 November
H2O columns
Version 3.53, 25 October-10 November
BIAS-2 (ch ): all negative values
version 4.0 positive values but orders of magnitude too high
BIAS-1 (ch ): values between 0 en 3 x 10^5 kg m-2
1% of pixels is negative (not counting sza > 85 )
BIAS-0 (ch ): non-physical values, large spread with small given errors, many ‘normal’ values around 10 to 20 kg m-2.
0.1% of pixels is negative.

9. H2O columns

10. Intercomparison of H2O columns
Direct solar observations with
IR spectrometer
The nearest SCIAMACHY pixel is selected
within a 500 km range from the GB station
COMPARISON OF SCIAMACHY WITH GROUND-BASED MEASUREMENTS-AOID427

11. Intercomparison of H2O columns
 Sciamachy data
* Integrated radiosonde
* Closest Sciamachy pixel
Mean difference : -33 %
St. dev.: 35 %

12. Intercomparison of H2O columns
 Sciamachy data
* Integrated radiosonde
* Closest Sciamachy pixel
Mean difference: 90 %
St. dev.: 220 %
* Integrated radiosonde/ozonesonde
 Sciamachy data
Sonde data from Bogumil Kois, IMWM, Legionowo, Poland

13. Intercomparison of H2O columns
Int. sonde on 29 oct =
15.4 kg/m2
Int. sonde on 5 nov =
10.0 kg/m2

14. Conclusions
Sciamachy columns of CO, CH4 and H2O show non-physical values, orders of magnitude too high, negative values, large spread, constant values at high sza (close to gb values).
Given the current status of these products, comparing with groundbased measurements does not give any additional information
BrO, ClO, SO2, H2CO: not in the distributed products yet
CO2, N2O: too unrealistic to do any comparisons
(CO2 = 0, N2O orders of magnitude too large)