WIND

 

Click the link for  Wind Quiz.  If you need help, read the notes below.

Wind is the movement of air around the earth. It is basically caused by the uneven heating of the earth's surface. Warmer, lighter air is pushed along by heavier, cooler air. Other factors affecting wind include whether the particular place is close to land or water, the seasons of the year, the topography of a place, etc..

Wind direction is measured by a wind vane which is an arrow mounted on top of an elevated site. The wind vane is designed so that its arrow points into the wind. With a compass aligned with the arrow, one can determine the direction of the wind. animated anenometer

Wind speed or velocity is measured with either an anemometer or radar. The anemometer, pictured above, consists of several cups mounted sideways and extended out on a rotating axis or pole. The cups catch the wind and the more turns of the attached cups, the greater the wind speed.

Doppler radar is also used to measure wind speed. It works like a police radar gun aimed at speeding cars, but in this case is aimed at speeding winds with microwaves.

 

Wind Description
Miles per hour
Calm 0
Light air 1-3
Light breeze 4-7
Gentle breeze 8-12
Moderate breeze 13-18
Fresh breeze 19-24
Strong breeze 25-31
Moderate gale 32-38
Fresh gale 39-46
Strong gale 47-54
Storm 55-63
Violent storm 64-73
Hurricane Above 73

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