Geography Climatology Summary

, 1. Global Air Circulation:
 The earth’s axis is titled at 23,50 to the vertical.
 Main cause of the different seasons and as the
earth revolves around the sun each place on earth
will receive a different amount of sunlight.
 Cause the AIR PRESSURE to change which causes
wind and weather to change.

, Primary Circulation:
 Equatorial areas = receive a lot of heat (direct
sunlight) and thus the air RISES forming a low
pressure cell.  Equatorial Low Pressure

 Polar areas = receive little sunlight or insolation
(incoming solar radiation) and thus they
experience high pressure cells.  Polar High
Pressure

, Primary Circulation:
 The air rises near the equator, it cools and then
descends at about 300 from the equator.
 At 600 N & S of the equator the warm air from the
300 region and the cold air from the poles
converge – these two air masses have different
characteristics (density and moisture) AND DO NOT
MIX – warmer air rises over colder air forming
another LP.
 The 4 zones will shift north and south as the sun’s
rays move between the tropics.