1. 500 hPa height , surface pressure
2011 Feb 1 12Z
Smaller scale features less evident in middle/upper troposphere

2. 850 hPa , Feb 04-06
Feb 05
Feb 06
Feb 04
Svnoptic scale cyclones can develop rapidly (1-2 d.) and move generally eastward

3. 02/02/2009
sfc
500 hPa
Upper level trough westward of surface frontal low pressure

4. Feb Z
Feb Z

5. Feb Z
Feb Z

6. Jan 500 hPa climatology
Quasi-stationary
planetary-scale waves

7. Jan 850/500/300 hPa climatology
little if any phase shift with height (in the troposphere)

8. Observed zonal mean u, T
DJF
JJA

9. Observed zonal mean u, T
DJF
tropopause
JJA

10. Observed zonal mean u, T DJF JJA cold winter polar stratosphere
high, cold, tropical tropopause
JJA
very flat T contours in tropics

11. Observed zonal mean u, T
DJF
main tropospheric (subtropical) jets
JJA

12. Observed zonal mean u, T DJF JJA midlatitude surface westerlies
tropical easterlies

13. Observed zonal mean u, T DJF JJA
polar night jets in winter stratosphere
JJA
summertime stratospheric easterlies

14. Mean meridional circulation DJF
V ~ 1 m/s

15. Mean meridional circulation DJF
Hadley cells
Ferrell cells

16. Seasonal variation of the Hadley circulation

17. Different averaging approaches (Townsend & Johnson, JAS, 1985)
mass streamfunction
Average at fixed p
Average at fixed θ