1. Recall that AIR TEMPERATURE varies dependent upon
• the specific heat capacity of the surface
• the angle of the sun
• the tilt of the Earth on it’s axis
The result is an ENERGY IMBALANCE, which creates imbalances in
• temperature
• density
• water vapor
• pressure

2. The equatorial regions receive the greatest energy
• Heated air is less dense, rises
• At altitude it cools and sinks
cooler air holds less water vapor, so clouds form
• Creates vertical air flow

3. • Dense, sinking air at the surface creates flows into replace the rising air
• Horizontal flow as air moves from high to low pressure
• Creates surface winds

4. Effect: Global regions of high and low pressure

5. Effect: Global winds pressure Still, sinking air = horse latitudes
Surface winds move air from high to low pressure
Still, rising air = doldrums

6. Effect: Planet-wide bands of clouds
Here

7. Net effect is to create a set of convection cells that circulate roughly N/S, creating winds that move air E/W

8. A set of convection cells are
created every 30 degrees of latitude

9. Plus E/W winds

10. Well, maybe not so simply….