Stratospheric Dynamics and Chemistry

1. Stratospheric Dynamics and Chemistry Michel Bourqui, Farid Ait Chaalal, Thomas Milevski, Ryan Muncaster, Andrew Ryzhkov, Barbara Winter

2. What is the Stratosphere ? Winter Summer WMO, Scientific Assessment of Ozone Depletion: 2002

3. How is the Stratosphere Working ?

4. Vertical structure of the temperature Source: eiu.edu

5. The Global Circulation Summer Winter W = westerly wind E = easterly wind Stratospheric circulation Tropospheric circulation

6. The Global Circulation Summer Winter W = westerly wind E = easterly wind Stratospheric polar vortex

7. The stratospheric chemistry stratopause tropopause Pole Equator Pole

8. The stratospheric chemistry stratopause tropopause Pole Summer Equator Winter Pole

9. The stratospheric chemistry stratopause UV O2 O3 tropopause Pole Summer Equator Winter Pole

10. The stratospheric chemistry stratopause UV O2 O3 tropopause Pole Summer Equator Winter Pole

11. The stratospheric chemistry stratopause UV O2 O3 tropopause Pole Summer Equator Winter Pole

12. The stratospheric chemistry stratopause UV O2 O3 tropopause Pole Summer Equator Winter Pole

13. The stratospheric chemistry stratopause UV O2 O3 tropopause Pole Summer Equator Winter Pole

14. The stratospheric chemistry stratopause UV O2 O3 tropopause density Pole Summer Equator Winter Pole

15. Morphology of the ozone layer Ozone concentration, averaged along parallels, for Dec – Jan – Feb of 1979 (pre- ozone hole period) 1012 molecules cm-3 Ozone layer Altitude (km)

16. How is the Stratosphere Working ? Middle atmosphere: Dynamics/Transport Chemistry Radiation

17. How is the Stratospere Working ? Lower atmosphere: Dynamics/Transport Chemistry Radiation

18. Recent Advances in Stratospheric Research Modelling: • 3D Chemistry-Climate Models: first inter-comparison 2002 • Chemical data assimilation: research is starting now… Observation: • Ozone observation by satellite since 1990s • Envisat (EU) satellite: launched March 2002 (chemical composition) • Aura (USA) satellite: launched January 2004 (chemical composition) • ACE (CA) satellite: launched May 2003 (chemical composition) • ADM (EU) satellite: will be launched in 2007 (winds) • WINDII (CA) satellite: projected for 2009 (winds)

20. Our current research • Effect of climate change on the ozone layer • Development of a fast chemistry scheme • Chemical data assimilation • Transport, mixing and chemistry • Non-linear chemistry in turbulent flows • Stratosphere-troposphere exchange • Solar variability and ozone layer

21. Our current research • Effect of climate change on the ozone layer • Development of a fast chemistry scheme • Chemical data assimilation • Transport, mixing and chemistry • Non-linear chemistry in turbulent flows • Stratosphere-troposphere exchange • Solar variability and ozone layer

22. The effet of climate change on the Ozone Layer

23. Ozone depletion due to CFCs Ozone column observations (ground-based, WMO 1998) (DU) CFC scenario (A1), tropospheric concentration, (WMO 1998) (DU)

24. 3D Chemistry-Climate Model Forecasts of Ozone Recovery (From Austin et al. 2003)

25. 3D Chemistry-Climate Model Forecasts of Ozone Recovery (From Austin et al. 2003)

26. CO2 Effects of Greenhouse Gases on Ozone Layer ? GHG scenarios, tropospheric concentrations (WMO 2001) (WMO 1998, WMO 2001) CH4 N2O CFCs Changes in stratospheric ozone between 1979 and 2060?

27. Potential effects of increasing GHGs on stratospheric ozone: Increasing concentrations of greenhouse gases (GHGs) : CO2, N2O, CH4, … (Low concentration of Cly) Chemical effects (mainly due to N2O and CH4) Radiative effects (mainly due to CO2) Dynamical effects (???) Changes in the distribution of stratospheric ozone Changes in the total ozone

28. Chemical and radiative effects for August Total ozone change:

29. Chemical and radiative effects for August Total ozone change: Separated effects of: Chemical ozone loss increased due to larger N2O concentration N2O Chemical ozone loss slowed down due to temperature decrease CO2

30. Dynamical effects...

31. Potential effects of increasing GHGs on stratospheric ozone: Increasing concentrations of greenhouse gases (GHGs) : CO2, N2O, CH4, … (Low concentration of Cly) Chemical effects (mainly due to N2O and CH4) Radiative effects (mainly due to CO2) Dynamical effects (???) Changes in the distribution of stratospheric ozone Changes in the total ozone

32. Transport, mixing and chemistry • Non-linear chemistry in turbulent flows • Stratosphere-troposphere exchange

33. Transport, mixing and chemistry Winter Summer WMO, Scientific Assessment of Ozone Depletion: 2002

34. Transport, mixing and chemistry Instantaneous tropopause (2 PVU from ECMWF data) Climatological tropopause PVU SH NH

35. Transport, mixing and chemistry Animation of horizontal cross-section of the tropopause: click here

36. Transport, mixing and chemistry A study of the interaction between chemistry and fluid dynamics at the tropopause Water vapour OH Ozone Animation of OH: click here

37. Transport, mixing and chemistry A study of non-linear chemistry (A+B→C) in turbulent flows Increasing diffusion,decreasing resolution C concentration time

38. Transport, mixing and chemistry Studies of Stratosphere-Troposphere Exchange (STE) • High resolution simulation of stratosphere-troposphere exchange episodes • Development of a theoretical stochastic model for global STE • Characterisation of dilution rate of stratospheric air in the troposphere • Impact of STE at the ground and origin of surface air

39. Transport, mixing and chemistry Studies of Stratosphere-Troposphere Exchange (STE) • High resolution simulation of stratosphere-troposphere exchange episodes • Development of a theoretical stochastic model for global STE • Characterisation of dilution rate of stratospheric air in the troposphere • Impact of STE at the ground and origin of surface air

41. Transport, mixing and chemistry Rapid transport between the boundary layer and the stratosphere Winter Stratosphere Stratosphere tropopause tropopause 700 hPa 700 hPa Boundary layer Boundary layer Calculation based upon ERA15 (1979-1993)

42. Solar variability and ozone layer • Our approach: • Use a magneto-hydrodynamic model of the Sun to generate solar variability (with spectral resolution) • Force the photochemical scheme as well as the radiation scheme in our Climate-Chemistry Model troposphere-stratosphere chemistry-climate model.

43. Solar variability and ozone layer Froelich & Lean 2006

44. Solar variability and ozone layer Courtesy: Paul Charbonneau, Universite de Montreal

45. In Summary: Research Tools Research Focus • General Circulation Models • Mesoscale Models • Chemistry models • Trajectory models • Meteorological data (ERA40,…) • Satellite data • Stratosphere • Transport and dynamics • Chemistry • Chemical data assimilation • Ozone layer • Climate • Solar Variability • Future satellite mission STEP Research Collaborations • University of Toronto • Universite de Montreal • University of Saskatchewan • Canadian Space Agency • MSC (Dorval and Toronto) • University of Reading (UK) • ETHZ (Switzerland) • + many others Research Infrastructure • Supercomputer • Desktop computers

46. Further information http://www.meteo.mcgill.ca/bourqui http://www.meteo.mcgill.ca/hydroxyl Office: BH 815 Email: michel.bourqui@mcgill.ca