1. Dynamical Influence on Inter-annual and Decadal Ozone Change http://www.iup.physik.uni-bremen.desandip@iup.physik.uni-bremen.de Sandip Dhomse, Mark Weber, J.P. Burrows Universtät Bremen FB1, Institüt für Umweltphysik (iup)

2. Outline Introduction Data used Inter-annual variability Decadal variability Tele-connection patterns (Introduction) Summary and Conclusion Outlook sandip@iup.physik.uni-bremen.de 11/11/03

3. No abrupt change in chemical composition Introduction sandip@iup.physik.uni-bremen.de 11/11/03 Sun - at the same position

4. sandip@iup.physik.uni-bremen.de 11/11/03 Total Ozone is higher in NH (spring) than SH (spring) Low TOZ In tropics Relatively High TOZ in tropics during SH spring

5. Wave activity controls Stratospheric circulation Stratosphere Troposphere Exchange sandip@iup.physik.uni-bremen.de 11/11/03 Holton et al., 1995

6. SH winter- colder sandip@iup.physik.uni-bremen.de 11/11/03 Mean Winter temp. (shaded) And zonal wind (contour) for NH and SH SH – polar jet stronger Tropopause colder during NH winter

7. Planetary waves Planetary waves are large-scale distortions to the mean flow The flow (black) meanders across latitude circles (blue). V V sandip@iup.physik.uni-bremen.de 11/11/03

8. Examples of wave patterns Wave 1 pattern Wave 2 pattern sandip@iup.physik.uni-bremen.de 11/11/03

9. Brewer-Dobson circulation Breaking planetary waves apply a FORCE to the winds- decelerates the speed Pressure gradient force- remains unaffected Corioli’s force - REDUCED so there is a net force towards the pole. Air RISES over the equator, drifts steadily POLEWARD (while meandering around the latitude circles) and SINKS at the poles sandip@iup.physik.uni-bremen.de 11/11/03

10. Two components of EP flux are calculated as,(Andrews,et.al 1987) And its divergence is Eliassen Palm (EP) flux vector is a measure of the upward propagating momentum carried by planetary waves The divergence of EP flux gives the volume where momentum is deposited Measuring the wave activity Heat flux Momentum flux

11. sandip@iup.physik.uni-bremen.de 11/11/03 Measuring the wave activity

12. sandip@iup.physik.uni-bremen.de 11/11/03

13. Data used Meteorological data set ERA40 -23 pressure levels ERA15 - 17 pressure levels UK Met. Office - 22 pressure levels ECMWF -21 pressure levels NCEP - 17 pressure levels Ozone data set GOME- total ozone data TOMS -total ozone data sandip@iup.physik.uni-bremen.de 11/11/ 03

14. Inter-annual variation of flux and Ozone High flux - increase in Brewer-Dobson circulation - more transport

15. sandip@iup.physik.uni-bremen.de 11/11/ 03 Record high lower stratospheric heat flux on 20th/21st September (ERA40 1960-2002) Splitting of the polar vortex on 26th September 2002 First major stratospheric warming in SH

16. sandip@iup.physik.uni-bremen.de 11/11/ 03 wave activity and winter gain in ozone Weber et al. 2003  High correlation between winter heat flux (wave activity) and spring/fall ozone ratio  Winter ozone gain in Antarctic 2002 presents an intermediate case between other Antarctic winters and cold Arctic winters (higher contribution from transport)

17. High Heat flux –Low PSC

18. sandip@iup.physik.uni-bremen.de 11/11/ 03 Does dynamics the same? Or Chemistry is changing? Model Differences ERA40 ERA40 +ERA15

19. sandip@iup.physik.uni-bremen.de 11/11/ 03 Decadal Variation? And Difficulties in trend analysis

20. sandip@iup.physik.uni-bremen.de 11/11/ 03 Northern Hemisphere

21. sandip@iup.physik.uni-bremen.de 11/11/ 03 Tropics (50 hPa) One of longest westerly phases of QBO (1993-1996)

22. sandip@iup.physik.uni-bremen.de 11/11/ 03 tropics Polar Mid-latitudes

23. sandip@iup.physik.uni-bremen.de 11/11/ 03 No SSW since last 17 years in Jan. -1.2 K/decade in Nov. and Dec.

24. sandip@iup.physik.uni-bremen.de 11/11/ 03 SH – pre-satellite period – Problem?

25. sandip@iup.physik.uni-bremen.de 11/11/ 03 PSC volume using ERA40 data T <195 K (PSC volume) SH (JAN-DEC)NH (JUL-JUN)

26. sandip@iup.physik.uni-bremen.de 11/11/ 03 Days (Jul-Jun) 195 K- PSC temperature SH –colder temperature Days (Jan-Dec)

27. sandip@iup.physik.uni-bremen.de 11/11/ 03 No significant trend in heat flux

28. sandip@iup.physik.uni-bremen.de 11/11/ 03 Different models – different trends

29. sandip@iup.physik.uni-bremen.de 11/11/ 03 No significant trend in any dataset in heat flux as well as EP Flux

30. sandip@iup.physik.uni-bremen.de 11/11/03 Summary Strong correlation between seasonal heat flux and total ozone in March. No significant trend on seasonal scale in heat flux. Maximum cooling trend is in November and January ( -1.2 K/decade), but there is not trend in heat flux. Different models, different periods lead to different trends.

31. sandip@iup.physik.uni-bremen.de 11/11/03 Bremen- 10/23/2003

32. sandip@iup.physik.uni-bremen.de 11/11/03 Arctic Oscillation

33. sandip@iup.physik.uni-bremen.de 11/11/03 Arctic Oscillation From National Geographic Magazine March-2000

34. sandip@iup.physik.uni-bremen.de 11/11/03 Arctic Oscillation source : http://www.ldeo.columbia.edu

35. sandip@iup.physik.uni-bremen.de 11/11/03 28% 30% 45%

36. sandip@iup.physik.uni-bremen.de 11/11/03 13% 25% 12 %

37. sandip@iup.physik.uni-bremen.de 11/11/03 8% 11%

38. sandip@iup.physik.uni-bremen.de 11/11/03 Conclusion There are no significant trends in 2D (latitude & altitude) analysis of the data. 3D analysis of data will be useful to find the dependence of ozone on different tele- connection patterns. EOF analysis is good tool for 3D analysis.

39. sandip@iup.physik.uni-bremen.de 11/11/03 Outlook Study ozone dependence on different tele- connection pattern using EOF technique. Find out different patterns in the ozone variability using GOME vertical profile data (neural network), TOMS, SAGE, POAM, ozonesonde datasets.

40. Thank you very much for your kind attention!!! sandip@iup.physik.uni-bremen.de 11/11/03