# What is wind?

```Quiz Time
You will have a short quiz about temperature and wind on ___________________.
Please work with your group to complete the review sheet below so you can take it
home to practice and study.
1.
Draw and explain how warm air and cool air are different.
2. How is wind created?
3. Fill in the diagram below showing how air moves in a room. Use red crayon to
show warm air and blue crayon to show cool air.
4. What tool is used to measure wind speed?
5. What tool is used to measure wind direction?
Measuring the Wind
There are two aspects of wind we can measure: wind speed and wind direction.
Wind Speed
Measuring wind speed is done by a tool called an anemometer (an-uh-mom-iter).
The wind (moving air) pushes against the cups and causes them
to turn. When the cups turn, they cause a meter to spin, which
tells how fast the wind is blowing.
Wind Direction
When we talk about wind direction, we tell what direction the wind is coming from.
For example, when you hear the weather man say, “Today we will have a West
wind”, that means the wind is coming from the West and moving toward the East.
To show wind direction you will see wind socks or weather vanes.
Where’s That Wind Come From?
What is wind?
Wind is air in motion. It is produced by the uneven heating of the earth’s surface by the
sun. Since the earth’s surface is made of various land and water formations, it absorbs the
sun’s radiation unevenly. Two factors are necessary to specify wind: speed and direction.
What causes the wind to blow?
As the sun warms the Earth's surface, the atmosphere warms too. Some parts of the
Earth receive direct rays from the sun all year and are always warm. Other places receive
indirect rays, so the climate is colder. Warm air, which weighs less than cold air, rises.
Then cool air moves in and replaces the rising warm air. This movement of air is what
makes the wind blow.
Air in Motion
Since warm air rises, the upper air in the room will be the warmest. Other places
in the room that also may be warmer will be areas exposed to direct sunlight,
particularly during the warmer seasons.
Darker coloured surfaces in direct
sunlight and the areas around the heat
vents may also be warmer. The coolest
areas will be next to windows during
the winter, especially those that face
north or west and areas next to exits
or doors where drafts occur.
```