1. Jim Angell’s contributions to understanding the QBO

3. QBO !

5. discovery of QBO

6. discovery of QBO Angell and Korshover 1962, 1963

8. Meridional structure of QBO from Angell and Korshover, 1963

9. Equatorial QBO derived from radiosondes and rockets Baldwin et al., 2001

10. Schematic of global QBO Baldwin et al., 2001

11. Angell and Korshover (1964) coin the term ‘Quasi-Biennial Oscillation’

12. Naming the QBO was not easy... kind-of biennial oscillation almost biennial oscillation not quite biennial oscillation somewhat biennial oscillation quasi-biennial oscillation

13. 50 hPa temps note out-of-phase between tropics and midlats

14. QBO temperature signal in lower stratosphere derived from regression with MSU4

15. Snapshot of temperatures and meridional circulation associated with the QBO note extension into winter midlats February 1994 out-of-phase vertical structure

16. Equatorial waves and the QBO

17. power spectra tropics subtropics midlats strong peak at 10-15 days

18. Idealized wave-mean flow interaction in QBO Kelvin waves only propagate in background easterly winds

19. zonal wind eddy power spectra Kelvin waves observed during easterly QBO winds

20. QBO effects on ‘centers of action’

23. Surface signal of QBO Baldwin et al., 2001

24. Holton-Tan effect

25. observations 1964-1996 SKYHI simulation (48 years) Holton-Tan effect (composited QBO E-W)

26. Meridional structure of QBO from Angell and Korshover, 1963 evidence of Holton-Tan effect

27. Ozone QBO

28. out of phase between tropics and midlats

29. total interannual variability QBO component Column ozone from TOMS

30. Vertical structure of ozone QBO at equator 2-cell structure

31. QBO signal in nitrogen dioxide (NO 2 )

32. QBO and stratospheric water vapor

33. stratospheric water vapor tropical tropopause temperature

34. QBO variations in stratospheric water vapor from HALOE satellite data, 1991-2003 Deseasonalized anomalies

35. Vertical propagation of QBO anomalies (interannual ‘tape recorder’)

36. HALOE H2O anomalies tropical tropopause temperature anomalies Stratospheric H2O anomalies are consistent with tropical tropopause temperature changes

37. Jim Angell’s contributions span all aspects of the QBO. * global structure and propagation * ozone * equatorial waves * coupling with troposphere * tropopause and stratospheric H 2 O Much of this original research is still relevant today!

38. Happy Birthday Jim! QBO