1. Characteristics of the Atmosphere

2. What is Earth’s atmosphere made of?
An atmosphere is a layer of gases that surrounds a planet or moon
The air you breathe is made of many different things.
Almost 80% of it is nitrogen gas
The rest is mostly oxygen, the gas we need to live.

3. Which two gases make up most of Earth’s atmosphere?
Reading Check
Which two gases make up most of Earth’s atmosphere?

4. Where do the gases in the atmosphere come from?
Where the gas come from
Oxygen
Plants give off oxygen as they grow
Nitrogen
Nitrogen is given off when dead plants and animals decay
Water Vapor
Liquid water evaporates and become water vapor
Plants give off water vapor as they grow.
Water vapor comes out of the Earth during volcanic eruptions
Carbon dioxide
Carbon dioxide comes out of the Earth during volcanic eruptions
When animals breathe, they give off carbon dioxide.
Carbon dioxide is off when we burn things that were once plant or animal material.

5. Name two gases that volcanoes contribute to the atmosphere.
Take a Look: Identify
Name two gases that volcanoes contribute to the atmosphere.

6. Air Pressure- is how much air above you weighs.
The higher you go, the lower the air pressure gets.

7. 4 Main Layers of the Atmosphere
Troposphere
Stratosphere
Mesosphere
Thermosphere

8. Troposphere The layer of the atmosphere that we live in.
Almost 90% of the gases in the atmosphere is here
The higher you move into the troposphere, both air temperature and air pressure decrease

9. Stratosphere Stratosphere = layers Temperature increases
Temperature increases because of a gas called ozone.
Ozone layer protects living things by absorbing harmful ultraviolet energy

10. Reading Check
Why is ozone in the stratosphere important for living things.

11. Mesosphere
Is above the ozone layer
Temperature drops again

12. Thermosphere Uppermost layer of the atmosphere
Temperature begins to rise again
Thermo= heat

13. Ionosphere
Auroras are curtains and ribbons of shimmering colored lights.
Please google auroras now to see what they really look like.

14. At what altitude does the mesosphere end and the thermosphere begin?

15. Answer the questions below by using the previous slide.
At what altitude does the mesosphere end and the thermosphere begin?
Where auroras occur?
What layer of the atmosphere will you find:
Space craft
Hot air balloon
People or animal
Meteors
Satellites
Commercial aircraft
Parachute jumper
Supersonic plane