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

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

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

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

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

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

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

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

11. Cargese UTLS ozone and ozone trends

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

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

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

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

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

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

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

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

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