1. Andy Delcloo and Hugo De Backer
Homogeneity of the long term ozonesonde observation record in the troposphere and the stratosphere for Uccle
Andy Delcloo and Hugo De Backer
Sparc/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, Januari
Sparc/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, Januari

2. Ozonesonde Ozone profiles Balloon soundings
Brewer-Mast sondes
Z-ECC-sondes since April 1997
3 x week: Mo-We-Fri
Sparc/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, Januari 2

3. Trends
Sparc/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, Januari

4. Trends
Sparc/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, Januari

5. Changes in the procedure to get to the best possible time series
Pump efficiency
Box temperature (taking into account)
Changes from BM  ECC sondes
Changes in pre-flight conditions
Altitude error
SO2 interference
Background current…
Standard correction <-> correction for temperature and pressure.
 ftp.kmi.be/dist/meteo/hugo/publ/1999/o3prof.pdf
Sparc/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, Januari

6. Standard <-> adapted correction
Boxtemperature is measured if available
Pump correction is replaced by pressure dependent correction to correct for total ozone by using measured total ozone column data.
Standard temperature
Fixed pump correction
Linear correction to correct for the total measured ozone column compared with the integrated total ozone column

7. Sparc/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, Januari

8. Which procedure can we apply to check for inconsistencies?
Use of SAGE-II data
Is a satellite which uses the principle of onion peeling
Use of auto-calibration !
Important if you want to look for discontinuities in time series
Time series used from 1985 – 1999
Change from BM  ECC 1997
Sparc/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, Januari

9. SAGE-II 26 _ 30 KM 26 _ 30 KM Using additional corrections
Using WMO standard corrections
Sparc/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, Januari

10. What about the quality of tropospheric ozone ?
Use of a chemical transport model: CHIMERE
ECMWF (50 km)
ERA-INTERIM
Sparc/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, Januari 10

11. CHIMERE simulation
Sparc/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, Januari 11

12. Cross-section O3-profile Uccle
5 km GL
Sparc/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, Januari 12

13. Capability of a CTM to catch vertical variability
Sparc/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, Januari 13

14. Capability of a CTM to catch vertical variability (1997 experiment)
Sparc/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, Januari

15. Integrated ozone profiles between 736 hPa and 541 hPa
Ozone anmaly (%)
Sparc/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, Januari 15

16. Procedure
Run 20 years of CTM output on a regional scale to identify the evolution of the day-to-day variability for free tropospheric ozone.
Different scenarios for emissions
Is the model able to explain differences in lower free tropospheric ozone concentrations between the three European ozone sounding stations
Emissions
Dynamical effects (meteorology)
Sparc/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, Januari

17. Conclusions
Anomalies for the higher stratospheric ozone concentrations have succesfully been homogenised through the apllication of supplementary correction factors taking into account
Boxtemperature
Pressure dependent correction
Lower free tropospheric ozone concentrations will be verified with CTM output
Sparc/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, Januari

18. Ozone, UV and aerosol group
Utsteinen – Antarctica – Princes Elisabeth station
Ozone, UV and aerosol group
UV Modelling
Radiative transfer for UV-index forecast
Sparc/IOC/WMO-IGACO workshop on Past Changes in the Vertical Distribution of Ozone, Geneva, Januari 18