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

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

• 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

Effect: Global regions of high and low pressure

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

Effect: Planet-wide bands of clouds Here

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

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

Plus E/W winds

Well, maybe not so simply….