1. Henk Eskes, ERS-ENVISAT symposium 2004 Retrieval, validation and assimilation of SCIAMACHY ozone columns Henk Eskes, Ronald van der A, Ellen Brinksma, Pepijn Veefkind, Johan de Haan, Pieter Valks Royal Netherlands Meteorological Institute (KNMI) 1) Ozone column retrieval 2) Validation of SCIAMACHY ozone columns 3) Data assimilation and validation

2. Henk Eskes, ERS-ENVISAT symposium 2004 Ozone column retrieval: new DOAS algorithm Heritage: Based on the OMI operational ozone column algorithm OMI-DOAS - Pepijn Veefkind, J. De Haan Implementation for GOME TOGOMI - P. Valks, R. Van Oss Implementation for SCIAMACHY TOSOMI - H. Eskes and R. van der A ESA ITT - GOME total-ozone algorithm BIRA IFE - University Bremen KNMI

3. Henk Eskes, ERS-ENVISAT symposium 2004 Innovations compared to e.g. GOME Fast Delivery, GDP vs 3 New treatment of rotational Raman scattering (J. de Haan) Empirical air-mass factor approach TOMS v8 ozone profile data base FRESCO cloud cover and cloud top height Radiative transfer improvements T-dep O 3 cross section: ECMWF temperature profiles

4. Henk Eskes, ERS-ENVISAT symposium 2004 Normalized Incident Sunlight Ozone Absorption Single Rayleigh Scattering Cabannes not scrambled 96.2 % Raman scrambled 3.8 % Ozone Absorption Ozone Absorption Received by sensor Rotational Raman: impact on retrieval

5. Henk Eskes, ERS-ENVISAT symposium 2004 New approach to rotational Raman scattering Difference between old and new treatment of Raman

6. Henk Eskes, ERS-ENVISAT symposium 2004 Empirical air-mass factor

7. Henk Eskes, ERS-ENVISAT symposium 2004 DOAS fit example rms 0.5 %

8. Henk Eskes, ERS-ENVISAT symposium 2004 SCIAMACHY TOSOMI Example

9. Henk Eskes, ERS-ENVISAT symposium 2004 Validation: midlatitude example Brewer De Bilt (52.1 N, 5.18E) bias: -1.8% rms: 4.3% No obvious seasonal bias

10. Henk Eskes, ERS-ENVISAT symposium 2004 Validation: summary Av. Bias [%] RMS BiasnumberAll-1.35.096 Dobson-1.14.554 Brewer-1.95.028 SAOZ-3.17.69 DOAS 4.98.13 other-1.15.42 Polar Lat >60-1.75.711 Lat<-60 1.16.57 Midlat Lat 30 to 60-1.44.951 Lat –30 to -60-4.06.36 (Sub)tropical Lat –30 to 304.321

11. Henk Eskes, ERS-ENVISAT symposium 2004 Validation: summary vs. latitude Main conclusions: Tosomi 1.5% lower than ground based RMS 4.9% increasing with ozone variability (representativity) No clear geographical location dependence No clear seasonal dependence

12. Henk Eskes, ERS-ENVISAT symposium 2004 Ozone data assimilation at KNMI TM3DAM assimilation code: Driven by 6h meteo from ECMWF (wind, temperature, pres): analyses and 10-day forecasts Same vertical levels as ECMWF (subset in lower troposphere) Second moments advection (Prather) Sub-optimal Kalman filter, detailed error covariance modelling Ozone chemistry parametrizations: Cariolle gas phase "Cold tracer" scheme for heterogeneous chemistry

13. Henk Eskes, ERS-ENVISAT symposium 2004 Assimilation: example

14. Henk Eskes, ERS-ENVISAT symposium 2004 Validation: RMS Tosomi retrieval - assimilation rms about 3% average total rms = retrieval + forecast + represent. DU

15. Henk Eskes, ERS-ENVISAT symposium 2004 Validation: RMS Tosomi retrieval - GOME-Togomi assimilation rms about 3% average total rms = retrieval + forecast + represent.

16. Henk Eskes, ERS-ENVISAT symposium 2004 Tropospheric Emission Monitoring Internet Service ESA-Data User Programme project Sciamachy ozone related products: Near-real time total ozone from Sciamachy, delivery to ECMWF for assimilation 9-day medium-range forecasts of ozone UV forecasts http://www.temis.nl/

17. Henk Eskes, ERS-ENVISAT symposium 2004 Summary / conclusions Tosomi: SCIAMACHY ozone column retrieval algorithm based on OMI-DOAS Validation with ground-based observations: No clear latitude dependence (or seasonal dependence) bias -1.5 % Validation with data assimilation: Important for the development of the retrieval implementation OmF: shows neutral lon-lat behaviour, rms 3% Data available on http://www.temis.nl/ Near-real time ozone columns, analysis records and 9-day forecasts of ozone and UV index 2004 ozone hole

18. Henk Eskes, ERS-ENVISAT symposium 2004 Validation of Tosomi retrieval with assimilation

19. Henk Eskes, ERS-ENVISAT symposium 2004 Validation of Tosomi retrieval with assimilation Theoretical error due to inaccurate lookup-table discretisation

20. Henk Eskes, ERS-ENVISAT symposium 2004 Validation of Tosomi retrieval with assimilation Before … DU

21. Henk Eskes, ERS-ENVISAT symposium 2004

22. Ozone hole 2004

23. Henk Eskes, ERS-ENVISAT symposium 2004 Ozone hole 2004 EP TOMS SCIAMACHY

24. Henk Eskes, ERS-ENVISAT symposium 2004 Ozone hole 2004