Why Wind Blows
A long time ago the Greeks thought wind was the breath of gods. They were happy with this explanation until the philosopher Anaximander realized there was a scientific explanation. I'm sure your teacher would agree with him. Here are a few facts you need to know about wind.
Breathe of Fresh AirWithout wind, we wouldn't have any change in the weather. That means no snowmen, no tans and no singing in the rain. Wind is air moving horizontally. It's the result of air movement over the Earth. Air moves because of pressure systems - it travels from areas of high pressure to areas of low pressure. The two reasons these pressures change around the earth are:
1. Earth Moves: As Earth moves, it drags the atmosphere around with it, which causes the air to mix with the higher level atmosphere. This creates turbulence and pressure systems.
2. The Sun's Heat: The air around Earth changes temperature all over, depending on the time of day. As the air warms up, it rises. In polar regions where the sunlight spreads over a greater area, the result is less warm air. This means the air over the poles is denser than the air over the equator.
As air rises, low pressure areas are created below. Air in high pressure areas then rushes to fill in the gap. If there's a big difference between the pressure, the flow of air between the two points will be stronger.
MeasurementsWind speed is measured by an instrument called an anemometer. It has three cups that catch the wind and causes the instrument to rotate. To make the wind speed official, the anemometer has to be 30 feet above ground. Downtown areas can be just as windy as the tops of mountains. Tall buildings on either side of the street can channel the wind, forcing it to blow much faster. The world record for the highest wind speed is 231 miles per hour. This was at the summit of Mt. Washington in New Hampshire.
Name that WindSome reoccurring winds have been named by meteorologists (scientists who study weather.) Here are a few wind names and a brief description of that wind.
Blue Norther: An arctic cold front moving into Texas.
Knik: A fast moving wind from the southeast to Palmer, Alaska.
Northeaster (also called Nor'easter): A strong wind linked with major storms and winter weather along the mid-Atlantic and New England areas. Squall:Most of the time, it's a sudden and violent wind caused by many continuous thunderstorms - usually over water. It can be over 100 miles long and bring rain and hail.
Chinook Wind: A warm dry wind that blows from the sea in some regions of the Pacific Northwest that causes a rapid rise in temperature.
Trade Wind: A wind blowing constantly in one direction. These winds mostly happen in the tropics.
Gale Warning: When winds reach between 32 and 53 miles per hour, the National Weather Services gives this warning.
Storm/Hurricane Warning: When winds reach between 54 and 74 miles per hour the National Weather Services also issue this warning.
Do you have any windy day stories? about it.