1. 1. Coriolis Deflection

2. 2. Atmospheric Processes
Air pressure differences create the global wind field.
Coriolis deflection causes winds to blow in the direction in which they do.
Air Pressure: P = density x g x height

3. 3. Equatorial atmospheric circulation – Walker cell
isobaric
surfaces
Walker
Cell
Strong convection in W Pac, Congo, Amazon

4. 4. Meridional air circulation cells
Trades - return flow in the Hadley/Walker cell system
4. Meridional air circulation cells

5. 5. http://www.ssec.wisc.edu/data/
Note the strong convection in: a) the western tropical Pacific, b) along ~5-10ºN (ITCZ), and c) along º (Polar Fronts) 5.

6. Animation of last 2 weeks of cloud cover

7. 6. Global Wind Fields

8. - Heat flux from equator to polar regions
HORSE LATITUDES
DOLDRUMS
Ferrel Cell
LOW
Produced by:
- Heat flux from equator to polar regions
- Coriolis effects on winds

10. 7. Global Air Pressure Distribution
Icelandic Low
Aleutian Low

11. 8. Summer/Winter Pressure Variations
Permanent Highs over Indian S Pac, S Atl,
Permanent Low over Southern Ocean
High over N Pac and N Atl modified by Aleutian Low and Icelandic Low

12. 9. Global wind speeds

13. Seasonal Variations of ITCZ and generation of Tropical Depressions

14. Seasonal excursion of the ITCZ

15. SE trades become SW when crossing the Equator to the N (Coriolis)
This generates a Tropical Depression

17. Similar variability of the ITCZ in the Pacific
Wind Convergence [δu/δx + δv/δy (10- 5 sec-1)]
(Liu and Xie, NASA)

18. 10. Location of formation of tropical storms/hurricanes
Steered by oceanic tropical anticyclone – Trades / Westerlies

19. 11.

21. Very rare hurricane in the South Atlantic – March 2004
(Movie of hurricane)