The global energy balance and atmospheric motion determine the circulation of the earth's atmosphere. There is a pecking order of motion in atmospheric circulation. Each process can be divided into ever smaller controlling factors. The global energy budget is an equal balance of short wave radiation coming into the atmosphere and long wave radiation going out. This is known as thermal equilibrium. The earth is in a state of thermal equilibrium; but we can have too much or too little energy in parts of the heat balance. If you have excess radiation warm air will rise, and a radiation deficit will make the air cool and fall. Air gets heated at the equator due to the inter tropical convergence zone and rises to the poles. At the poles the air is cooled and floats back down to the equator where the process is repeated.
             Another major contributing factor to the circulation of air is due to the subtropical highs. These highs similar to the inter tropical convergence zone migrate during the changing seasons. The belt model, shown in the text is a great representation of the general circulation of the atmosphere. The equatorial belt of variable winds ranges from 5 degrees south to 5 degrees north. This wind belt is characterized by weak winds and low pressure from the inter tropical convergence zone. As you go further north or south you encounter the Hadley Cells. Hadley cell circulation is caused by the movement of high pressure from the latitudes at 5 to 30 degrees north and 5 to 30 degrees south to low pressure areas around the equator. The movement of air from high pressure to low pressure causes convergence. This convergence generates the production of wind. The winds that are produced from this are the trade winds. The winds blow from a northern direction in the northern hemisphere, and in the southern hemisphere the winds blow from a southern direction. The trade winds comprise the largest wind belt. The westerlies lie in the Ferrell...