U2-T1

Question 1

Troposphere (def)

Answer 1

The layer of the atmosphere below the stratosphere, from ground level to 6 miles -10km

Question 2

Troposphere (degrees)

Answer 2

Between -50 and 20 degrees Celsius

Question 3

Troposphere pression

Answer 3

1/2

Question 4

Troposphere (% of gas in the atmosphere)

Answer 4

80%

Question 5

Stratosphere ( def)

Answer 5

The layer of the atmosphere that absorbs UV and contains the ozone layer. It is above the troposphere at an altitude of approximately 6 to 30 miles- 10 to 50km

Question 6

Altitude of the tropopause

Answer 6

10 km - 6 miles

Question 7

Stratosphere ( temperatures)

Answer 7

Between 10-20 km it is ~ stable at ~ -50 degrees C and then it’s getting warmer –> 0 degree at 50km of altitude

Question 8

Stratosphere (pressure)

Answer 8

In the first part : 1/10
In the second part (the higher one ): 1/100
Stratospause : 1/1000

Question 9

Stratosphere (% of gas in the atmosphere)

Answer 9

99.9% of gas in the atmosphere

Question 10

Stratospause (altitude)

Answer 10

50km - 30 miles

Question 11

Stratospause (pressure)

Answer 11

1/1000

Question 12

Mesosphere (altitude)

Answer 12

Between 50 km and 80km

Question 13

Mesophere (pressure)

Answer 13

Begin at 1/1000 (stratospause) and goes to ~ 1/10000

Question 14

Mesosphere (temperatures)

Answer 14

From 50 to 55 km it’s stable at ~0degree Cand then it gets colder until ~-90 degrees C

Question 15

Mesospause (altitude)

Answer 15

80 km

Question 16

Thermosphere (altitude)

Answer 16

From 80% to …

Question 17

Thermosphere (pressure)

Answer 17

First 20km at 1/1000000

Question 18

Proportion of nitrogen in the atmosphere

Answer 18

78%

Question 19

Proportion of the oxygen in the atmosphere

Answer 19

21%

Question 20

Proportion of the carbon dioxide in the atmosphere

Answer 20

0.038%

Question 21

Proportion of the rare gases (combined) in the atmosphere

Answer 21

1%

Question 22

Proportion of the methane in the atmosphere

Answer 22

0.00017%

Question 23

Ozone

Answer 23

0.000007%

Question 24

Proportion of the water vapour in the atmosphere

Answer 24

Very variable, up to 4% . It’s normally omitted as it is so variable so the % given for other gases are therefore for dry air

Question 25

What are the 2 most important processes maintaining the average composition of the atmosphere ? The 2 main processes maintaining the dynamic equilibrium

Answer 25

Photosynthesis and respiration

Question 26

Why fluctuations of carbon dioxide are greater in the summer than in winter?

Answer 26

Because higher light levels and temperatures make photosynthesis and respiration more rapid

Question 27

When occur long- term changes in atmospheric composition?

Answer 27

It occur with changes in the activity of the Sun, geological processes and increasingly, human actions

Question 28

Explain why the concentration of carbon dioxide in the atmosphere changes over a 24- hours cycle?

Answer 28

It rises at night as respiration occurs but photosynthesis cannot. During the day, photosynthesis is much more rapid than respiration so carbon dioxide levels drop

Question 29

Where naturally occurs more ozone?

Answer 29

In the stratosphere where ultraviolet light interacts with oxygen