Where does wind come from?

 

Where does wind come from?

The sun heats up the surface of planet Earth. The land heats up faster than water so the air above land is warmer than the air above the sea. Warm air rises and cooler air sinks.

This movement of air is called wind.

 

Flow of air

As the warm air rises, it starts to cool and form clouds, which move out to sea.

 

Sinking air

Cold, wet air sinks because it is heavier and closer together than warmer air. When it meets the sea it stops sinking.

 

Sea breeze

Cool air is sucked toward the land where the warm air has risen up. This movement is called the onshore breeze.

 

Land air

The warm air above the land rises because it is less squashed together than colder air. Warm air floats above colder air.

 

Weather patterns

Cold air from the North and South Poles sinks toward the warm equator, the imaginary line around the center of the Earth. The Earth’s surface near the equator is spun faster than the poles so the wind ends up moving toward the west.

 

Cold winds from the North Pole move south.

Cold winds from the South Pole move north.

 

How can we keep track of the wind?

 

Wind sock

A wind sock is an instrument that shows the direction the wind is blowing toward. The hollow tube is lifted as the wind blows through it. Wind socks are used at airports.

 

Anemometer

An anemometer is a machine that measures wind speed. Little cups catch the wind and spin around. The faster the wind moves, the faster they turn.

 

Quick quiz

1. Why is the air above land warmer than the air above the sea?

2. What is the name we give to the fastest type of wind?

3. What is the scale we measure wind on?