• It extends from 17 km to 50 km from the Earth’s surface.
• The ozone layer is located in the stratosphere. • Some of the highest clouds can be found in the lower stratosphere.
Go to Chapter 14, page 264, to learn more about the ozone layer.
Stratosphere Troposphere
20 km 15 km 10 km 5 km
: Figure 13.2 The layers of the Earth’s atmosphere
(i) Name two gases that make up the Earth’s atmosphere. (ii) Name two layers in the Earth’s atmosphere. (iii) Explain two differences between the stratosphere and the troposphere.
/ I understand that the Earth’s atmosphere is made up of gases. / I can name the layers of the atmosphere.
The sun Learning Intentions
In this section, you will learn: zz how the sun’s energy is the main source of heat for the Earth
zz how solar radiation is distributed around the globe.
Solar energy Solar
radiation Distribution
Hemisphere Equator Latitude Axis
Solar energy
Energy from the sun is called solar energy. Solar energy is the Earth’s main source of heat.
The energy that travels through space from the sun is called solar radiation. It is transmitted in the form of light and heat. Almost all of the energy that the Earth uses comes from the sun.
The amount of heat kept in the atmosphere depends on the amount of greenhouse gases in the atmosphere. We will learn more about the greenhouse effect in the next chapter.
30% of solar energy reflected back from the clouds
19% of solar energy absorbed by the clouds
51% of solar absorbed by the Earth
: Figure 13.3 How solar radiation heats the atmosphere 227
