Convection Currents

Convection Currents and Winds

A Review

Convection Currents

• On our planet, air is always on the move.

• This movement is caused by changes in air pressure.

• Warmer, less dense air rises.

• Cooler, more dense air sinks.

• The sun's energy provides heat, but Earth does not heat evenly.

High-Pressure Systems

In a high-pressure system, the molecules of cooled air are dense and create "weight" that pushes the air down towards the surface of the Earth.

Low-Pressure Systems

In a low-pressure system, the warmed air molecules spread out, become less dense, and rise above Earth's surface.

Multiple Choice

All locations on the planet do NOT heat evenly.

Where would we expect to find warmer areas on Earth?

• Near the equator

• Near the poles

Multiple Choice

What parts of the planet would be cooler?

• Near the equator

• Near the poles

Multiple Choice

What surfaces on Earth heat more slowly?

• Areas over land heat more slowly

• Areas over water heat more slowly.

Multiple Choice

What does air do as it is heated?

• Heated air rises.

• Heated air sinks.

Multiple Choice

What does air do as it cools?

• Cooled air rises.

• Cooled air sinks.

Multiple Choice

What areas on Earth lose heat quickest?

• Areas over land lose heat quickest.

• Areas over water lose heat quickest.

Multiple Choice

Air that cools becomes ___

• less dense and rises.

• more dense and sinks.

• less dense and sinks.

• more dense and rises.

Multiple Choice

The cooling and sinking of air creates ___ that usually brings light winds, fair weather, and sunny skies.

• high pressure

• low pressure

Multiple Choice

Air that is heated becomes ___.

• less dense and rises.

• more dense and sinks.

• less dense and sinks.

• more dense and rises.