Earth’s Atmosphere

Question 1

What is the atmosphere?

Answer 1

The layer of gasses that surrounds the earth, providing us with the air we breath and helping to regulate temperature and weather patterns.

Question 2

Whys the atmosphere important?

Answer 2

• it contains oxygen that living beings need to breath

• protects against meteorites

• shields against radiation and cosmic rays

• maintains earths temperatures

Question 3

What is the atmosphere made of?

Answer 3

A thin layer of gases surrounding earth; made up of nitrogen, oxygen, carbon dioxide, water vapour, and other gases (trace gases such as Ne, He, CH4, H2, Kr), as well as particles of liquids and solids.

Question 4

What are the percentages of nitrogen, oxygen, argon, and CO2 in our atmosphere?

Answer 4

Nitrogen = 78%
Oxygen = 20.9%
Argon = 0.9%
CO2 = 0.02%

Question 5

Why is nitrogen important in our atmosphere?

Answer 5

• essential nutrient - key ingredient for making things grow

• plant growth - to build important parts like leaves and proteins

• food chain - create the basis of the food chain (plants)

• healthy ecosystem - nitrogen in the air gets converted for plants to use, keeping ecosystems balanced and thriving

Question 6

Whys oxygen important in our atmosphere?

Answer 6

• respiration - humans and animals need it to breath through respiration

• fire support - O2 (oxygen) help things burn, like in fires and engines

• ozone layer - O3 (oxygen) forms ozone high in the atmosphere which shields us from harmful sun rays

Question 7

How does the atmosphere protect us?

Answer 7

Earth’s atmosphere makes conditions on earth suitable for living things, it traps energy from the sun keeping the earth warm and water in liquid form and protects Earth from dangerous radiation and meteor collisions.

Question 8

What are the layers of the atmosphere in order?

Answer 8

bottom to top

1. Troposphere
2. Stratosphere
3. Mesosphere
4. Thermosphere
5. Exosphere

Question 9

What is the altitude of each layer?

Answer 9

Troposphere = 0-12-18 km
Stratosphere = 11-50 km
Mesosphere = 40-50 to 80-90 km
Thermosphere = 80-90 to 800 km
Exosphere = 800 to 3000 km

Question 10

What is the temperature in each layer?

Answer 10

Troposphere = 15 to -56.5°C
Stratosphere = -56.5 to -2.5°C
Mesosphere = -2.5 to -86.5°C
Thermosphere = -86.5 to 1200°C
Exosphere = 1200°C

Question 11

How much of the mass of the atmosphere is in the troposphere?

Answer 11

75% even though it is the thinnest layer.

Question 12

What occurs in the troposphere?

Answer 12

Weather and we live in it

Question 13

Where is the troposphere thickest and thinnest? What’s it’s average thickness?

Answer 13

It’s thickest at the equator and thinnest at the poles, with an average thickness of about 12km.

Question 14

What is the the temperature of the air in the troposphere like?

Answer 14

It is warmest near the surface and the air cools as convection currents carry it upwards. The temperature drops until it levels off at the tropopause.

Question 15

What does the stratosphere contain and what is its job?

Answer 15

The ozone layer, which protects us from dangerous UV radiation.

Question 16

Why does the temperature increase in the stratosphere?

Answer 16

Ozone absorbs ultraviolet radiation from the sun, causing the temperature to increase throughout the stratosphere. The temperature increases until the stratopause (50km).

Question 17

What burns up in the mesosphere?

Answer 17

Meteorites

Question 18

Why does the mesosphere get cool again?

Answer 18

This layer does not absorb any energy from the sun, so it starts to cool again until the menopause around 85km.

Question 19

What is the air like in the thermosphere?

Answer 19

Very very thin!

Question 20

What are located in the thermosphere?

Answer 20

The international space station and the Aurora borealis.

Question 21

Why is the thermosphere so hot?

Answer 21

Solar radiation first hits this layer, so the particles here gain lots of energy. They move rapidly, so they have a very high temperature.

Question 22

Why does the thermosphere feel cold even though it is hot?

Answer 22

Because there are so few particles to transfer heat to you. Air is so thin you need special instruments to measure the temp.

Question 23

How long does the thermosphere extend?

Answer 23

690km

Question 24

How far does the exosphere extend?

Answer 24

For thousands of miles and gradually fades into space.

Question 25

What orbits in the exosphere?

Answer 25

Satellites

Question 26

What is altitude/elevation?

Answer 26

The distance above sea level. As altitude increases air pressure decreases, which also decreases density.

Question 27

What can low density of air cause?

Answer 27

Makes it difficult to breath because you have less oxygen

Question 28

What is air pressure?

Answer 28

The results of the weight of a column of air pushing down on an area; measured by an instrument called a barometer.

Question 29

What does gravity cause?

Answer 29

Air to be pulled down towards the earth’s surface

Question 30

What leads to greater atmospheric pressure?

Answer 30

There is more air pressing down at sea level than in the mountains.

Question 31

Why is carbon dioxide important in our atmosphere?

Answer 31

Greenhouse effect - the way in which heat is trapped close to Earth’s surface

Plant food - Photosynthesis acts as the lungs of our planet – plants use light and carbon dioxide (CO₂) to make the sugars they need to grow, releasing oxygen in the process