1. Cargese UTLS ozone and ozone trends 1 UTLS ozone and ozone trends D. Fonteyn (My apologies) Given by W. Lahoz (My thanks)

2. Cargese UTLS ozone and ozone trends 2 Importance UTLS relatively large (but variable) ozone trends very high climate sensitivity crucial region modulating stratospheric entry of tropospheric pollutants growing commercial aviation

3. Cargese UTLS ozone and ozone trends 3 Problems UTLS studies very complex region (dynamics and chemistry on a variety of scales) high demands on modeling capabilities limited amount of satellite observations with large uncertainties: rely on in-situ measurements

4. Cargese UTLS ozone and ozone trends 4 UTLS: combination of mixing and chemistry

5. Cargese UTLS ozone and ozone trends 5 Upper Troposphere: Emission of chemical species Ozone production Oxidation capacity Species influencing radiatif budget

6. Cargese UTLS ozone and ozone trends 6 Lower Stratosphere: Ozone destruction (ClOx, BrOx, NOx, heterogeneous chemistry) Species influencing radiatif budget

7. Cargese UTLS ozone and ozone trends 7 Upper Troposphere – Lower Stratosphere Studies: STE: Stratosphere – Troposphere Exchange Dynamical processes Chemical processes Climate All Linked

8. Cargese UTLS ozone and ozone trends 8 Overview of ozone chemistry?  Huge task  Chemical processes are relatively well known  Tropospheric chemistry  Stratospheric chemistry  Coupling with emissions, dynamics, climate change makes it extremely vast.

9. Cargese UTLS ozone and ozone trends 9 UTLS: ‘slow’ chemistry and ‘fast’ mixing

10. Cargese UTLS ozone and ozone trends 10 UTLS: distinct tracer relationships

11. Cargese UTLS ozone and ozone trends 11

12. Cargese UTLS ozone and ozone trends 12 Models & Observations: Climatology: dynamical features present in species distributions

13. Cargese UTLS ozone and ozone trends 13 >> Park et al, JGR 2004 Methane distribution at 136 hPa in July. Maximum near Asian monsoon and secundary maximum near North America

14. Cargese UTLS ozone and ozone trends 14 >> Park et al, JGR 2004

15. Cargese UTLS ozone and ozone trends 15 Models & Observations: Climatology Convective driven methane distribution, models agree with observations, gradients do not agree Lightning NOx production: qualitative agreement but not in vertical  Ozone ?

16. Cargese UTLS ozone and ozone trends 16 >> Kuell et al., JGR 2005 Detrended CFC 11 distribution at 100 hPa in the TRACHT region during the time period from 10–13 August 1997 as measured by CRISTA (upper map) and modeled by EURAD (interpolated to the CRISTA measurement grid; lower map). The EURAD data have a negative bias of about 20 pptv. Dynamical features: a mid-latitude blocking event characterized by an omega circulation pattern with a persistent cutoff low at its western wing.

17. Cargese UTLS ozone and ozone trends 17 Models & Observations: Satellite observations allow to detect dynamical effects in CFC 11 distributions on an event basis. Event modelling in qualitative agreement

18. Cargese UTLS ozone and ozone trends 18 Models & Observations: shifting towards event chemistry (UT): Brunner D., et al., ACP, 2005 An evaluation of the performance of chemistry transport models. Part 2: Detailed comparison with two selected campaigns

19. Cargese UTLS ozone and ozone trends 19 >> Brunner et al., ACP 2005

20. Cargese UTLS ozone and ozone trends 20 >> OUTLINE Composites of PEM-Tropics A time series. Measurements at 0–35 S and 400–200 hPa (about 7.2–12 km) only. Flight numbers are indicated at the top of each panel. Black: measurements.

21. Cargese UTLS ozone and ozone trends 21 >> OUTLINE Composites of SONEX time series. Only measurements between 350 and 200 hPa are included.

22. Cargese UTLS ozone and ozone trends 22 Models & Observations: shifting towards event chemistry (UT): Senistivity to emissions, biomass burning, lightning, aircraft …  Large model variability

23. Cargese UTLS ozone and ozone trends 23 Problems UTLS studies Other uncertainties, winds Bregman: mass conserving properties Comparing with MOZAIC aircraft campaign

24. Cargese UTLS ozone and ozone trends 24 >> Bregman, B., et al., ACP, 2003

25. Cargese UTLS ozone and ozone trends 25 Ozone UTLS trends Observations: – LS ozone depletion related and “recovery” –UT pollution effects VERY LONG term trends: models

26. Cargese UTLS ozone and ozone trends 26 >> WMO, 2002 Ozone decrease in lower stratosphere in Northern Mid-latitudes. The period 1980 – 2000 shows less decrease than 1980 – 1996.

27. Cargese UTLS ozone and ozone trends 27 >> OUTLINE Vertical discriminated deseasonalized ozone evolution from ozonesondes NH.

28. Cargese UTLS ozone and ozone trends 28 >> MOZAIC trends, Thouret, V., et al., ACPD, 2005 Time series of ozone monthly means in the UT over the three selected regions Europe, Eastern US and Iceland.

29. Cargese UTLS ozone and ozone trends 29 >> OUTLINE Time series of ozone monthly means in the LS over the three selected regions Europe, Eastern US and Iceland.

30. Cargese UTLS ozone and ozone trends 30 MOZAIC Ozone UTLS trends Apparent discrepancies: UT increase, high compared to literature LS increase, decreased expected  Effect of period, effect of location

31. Cargese UTLS ozone and ozone trends 31 >> GAUSS, M., et al., ACPD, 2005 Very long term trend: 1850 – 2000 Chemical change induced: Dynamical change induced:

32. Cargese UTLS ozone and ozone trends 32 A flavour of what to expect