What makes the wind blow?

A student in Ms. Paganis' class at Matigian Preschool in Libertyville asked: "Where does wind come from?"

Cool fall days, blustery spring days, wild windy summer thunderstorms, snowflakes blowing icy crystals around your face. All these weather conditions have wind in common. So what makes wind?

Air makes wind. A mixture of high-pressure air found near the Earth's surface and low-pressure air hovering atop mountain peaks combines to make moving air. That's wind.

"Nature is always trying to maintain a balance and as a result of this balance, wind is created," said 2nd Lt. Blake Hamilton, U.S. Air Force meteorologist. As the high and low pressure combine, air moves. That's called pressure-gradient force.

"The greater the pressure difference between two spots results in a higher pressure gradient, giving higher winds," Hamilton said.

Wind also is created by temperature. "Cold air is more dense than warm air," Hamilton said. "When the two air masses are close together, that forms a pressure gradient and nature will try to get that balance."

As the Earth rotates, wind is created. The sun's energy heats up some spots to scorching temperatures, and others, covered by shadows, stay cool. A combination of these forces keeps the wind blowing across the planet.

Winds blow and as they gain speed they create a gale force. Wind is harnessed to create electricity, to move sails on ships and to glide colorful kites across sunny blue skies.