Air exerts a downward pressure, which is referred to as atmospheric pressure. Air pressure is measured with a barometer. However, the air higher up is less affected. The difference between the speed at which air moves close to the surface and the speed of air higher up forms vortexes or whirlpools. Additionally, the sun warms the earth and the atmosphere.
Heating is greater at the equator than at the earth's poles.
Warm air rises while cold air sinks. Fans or blades are fixed to a shaft on a wind mill or wind turbine. They are set at an angle such that the air striking them forces them to turn. History of Wind Use Wind has been harnessed for energy for thousands of years. The first sailing ships used wind at least five thousand years ago.