Wind What is wind How does it blow

Wind • • • What is wind? How does it blow? How to mesure wind? The coriolis effect. Uses of wind.

What is wind? Wind is moving air. The Sun heats up some parts of the Earth more than others and the wind spreads this heat more evenly around the world. The map shows the main world and local winds. Local Winds affect the weather and are given special names in many parts of the world.

How does it blow? Air moves because of differences in pressure around the world. It blows from a high- pressure area to a low- pressure area. Differences on air pressure are caused by difference on air temperature.

How to mesure wind? The Beaufort Scale was invented in 1805 by Admiral Beaufort to estimate wind speed through observations of objects. The original scale was for use at sea but it has been adapted for use on land.

Sea Breezes and Land Breezes On a hot, sunny day the land heats up more quickly than the sea. Because of this air rises over the land cool sea breezes rush in to replace it. This is called Sea Breeze. By evening sea breezes can reach 200 km inland. At night land cools down more quickly than the sea so the breeze blows out from land to sea.

The coriolis effect. The Earth spins on its axis, which affects the direction of the wind. In the Northern hemisphere winds are swung to the right, and in the Southern to the left. This is called the Coriolis Effect. This is one of the factors affecting the wind direction.

Uses of wind A. Windblown Ship designers are building sailing ships to take the advantage of the wind. B. Wind power Windmills were once used to grind wheat to make flour. Today they are being used to generate electricity. The windmill at Tvind, Denmark is over 50 m high with three blades, each over 5 tones. It can produce enough electricity to light up about 120 homes.

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