1. Preliminary comparisons of GOMOS and MIPAS ozone products with Odin
AOID 760
Donal Murtagh, Ashley Jones, Patrick Eriksson, Carlos Jimenez
Chalmers University of Technology
Andreas Jonson
Stockholm University
+ Odin Teams

2. Aims
To provide cross-validation of Odin and ENVISAT measurements of atmospheric constituent profiles.
To assess errors and biases in the data from different instruments
To help improve data products from both platforms

3. Methodology
Assimilation of Envisat measurement data into the DIAMOND model during an extended period to ensure good model measurement agreement
Comparison with Odin and Sonde measurements obtained during the period.
Chosen period : 24/10/2002 to 06/11/2002
Odin data available during 8 of the chosen days

4. DIAMOND (Dynamical Isentropic Assimilation Model for OdiN Data)
Forecast model:
Transport scheme on isentropic surfaces
ECMWF winds
100 km grid spacing
Assimilation scheme:
Statistical interpolation/ Optimal Estimation
analysis errors, model error growth
Observations for model evaluation:
UARS MLS O3 version 4 and Odin SMR data

5. Setup for the Envisat Comparisons
DIAMOND model modified to use MJD as the time coordinate
Vertical coordinate 400 – 1000 K potential temp in steps of 50 K ( ~2 km)
Run for MIPAS ozone and N2O profile data for the period 24/10/2002 to 06/11/2002 = MJD – 52584
Some runs have also been made for the GOMOS reference set but not reported on here due to lack of overlap with other measurements

8. Composite plot Initial Model values against Mipas

9. Composite plot Model against Mipas-O3 after 10 days assimilation

10. Composite plot Model against Mipas–N2O after 10 days assimilation

11. Comparison with Balloon sondes
Selected sondes during the assimilation period have been compared to the closest model point at the same time as the balloon ascent.

12. Balloon Sonde Comparisons
Ny Ålesund 30/10/2002
Payern 28/10/2002

13. Odin Comparisons
Most comprehensive Ozone Validation for Odin products has been carried out for the Optical Limb scattering inversions using the Flittner Method (CvS)– Agreement with independent data is better than 10% on an individual profile basis
Comparisons of the 501GHz Sub-mm data have been carried out against the co-located Flittner profiles

14. SMR 501 GHz Ozone vs Flittner

15. MIPAS / Odin Ozone comparision

16. MIPAS / Odin SMR 501GHz Ozone comparision

17. MIPAS / Odin SMR 501GHz Ozone comparision

18. MIPAS / Odin SMR 501GHz Ozone comparision

19. MIPAS / Odin SMR 501GHz N2O comparision

20. MIPAS/Odin N2O comparision

21. MIPAS/Odin N2O comparision

22. Conclusions and Future Work
MIPAS Ozone and N2O products seem to be in good agreement with Odin measurements and balloon sondes.
More work required to put this on a quantitative basis and to look for biases.
Model will be properly tuned for N2O and the spatial characteristics of the data sets
Monitoring mode will be introduced to allow direct comparison of assimilating data sets and independent data