1. THE ATMOSPHERE

2. The atmosphere is the gases which surround the earth
They have no odour or colour
The atmosphere is made up of
78% Nitrogen
21% Oxygen
1% other gases

4. The Earth’s Atmosphere

5. The Earth’s Atmosphere

6. The atmosphere is important because
It provides us with the air we breathe
It absorbs heat from the sun during the day
It keeps heat in at night
It protects us from harmful rays of the sun

7. The atmosphere The atmosphere is made up of a few layers
Almost all clouds and water vapour are found in the layer of the atmosphere closest to the surface of the earth
This layer is called the TROPOSPHERE
This is the layer in which weather occurs

8. The troposphere

9. The troposphere

10. Life on earth would not survive without the atmosphere

11. THE SUN

12. THE SUN The sun is a huge star at the middle of the solar system
The heat from the sun is called solar energy
Solar energy provides heat and light to the atmosphere and to the surface of the earth

13. How the atmosphere is heated:
The earth’s surface absorbs heat from the sun. This heats the earths surface
The surface of the earth slowly lets this heat out, which warms the air close to the ground- RADIATION
The hot air rises because hot air is lighter than cold air- CONVECTION

14. Convection

15. The sun heats the earth unevenly
The temperature of a place depends on its position on the earth’s surface... Or the latitude of that place
Latitude is the distance north or south of the equator… who knows what the equator is?

17. Latitude
The equator an imaginary line drawn around the centre of the earth
It is at 0° latitude

20. Low latitudes…
Places near the equator are said to be in low latitudes, and are usually hot
The sun is almost directly above the equator all year, so its rays hit the surface from directly overhead
These rays cover little ground and so give a lot of heat

23. High latitudes…
Places far away from the equator are said to be in high latitudes, and are usually cold
At higher latitudes, far from the equator, the sun’s rays are slanted
This means they cover a lot of ground and so give little heat

25. JOURNEY OF EARTH AROUND THE SUN

27. homework
Draw a diagram of the earth with the equator drawn in- pg 82, fig 12.2
Draw a diagram of how the earth’s surface is heated unequally by the sun- (pg 83, fig. 12.4), and explain this diagram