Re: What exactly makes the wind, and where does it come from?

Wind is the movement of air set up by the unequal heating of the earth's surface by the sun. The movement of air is in the form of a convection current. When air next to the earth is heated, it expands and becomes lighter. This warmer, lighter air is pushed up by the colder, heavier air that surrounds it. The colder, heavier air now is heated and becomes lighter, being pushed up in turn by more cold, heavy air that surrounds it. This process continues until there is a steady flow of air, called a convection current, with warm air rising and cold air falling. Cold air is heavier so it exerts a greater pressure than warm air. Winds are formed when cold air from high pressure areas move to low pressure areas where the air is warmer.

There is a constant movement of air over the entire earth in the form of wind belts. Because the earth rotates, the movement of air over the earth becomes more complicated. The winds in the northern hemisphere are deflected to their right and the winds in the southern hemisphere are deflected to their left. As a result, a series of wind belts is produced around the earth, with the winds in each belt moving in a definite direction. Because the sun's rays shine differently on the northern and southern hemispheres in the summer and winter, the wind belts shift with the seasons.