Atmosphere Facts

Question 1

Air is composed of what

Answer 1

78% Nitrogen
21% oxygen
1% other gases (don’t forget water overall is made up of ONLY 1% of total gases in atmosphere)

Question 2

First layer of atmosphere + key figures

Answer 2

Troposphere
75% of air mass here
Almost all water vapour here
Higher in equatorial regions

Equator - 16km (60,000ft)
Mid Latitudes - 11km
Poles - 8km (26,000ft)

Question 3

Second layer of the atmosphere + key figures

Answer 3

Stratosphere

Constant temp up to 20km (65,000ft)

After 20km ozone causes an increase in temperature (Absorbs short wave UV)

Low density/lacks weather (nacreous clouds)

-56.5 degrees up to 0 degrees

Question 4

Third Layer of atmosphere

Answer 4

Mesosphere
50km to 90km

Getting cold again
0 degrees down to -90 degrees

Question 5

4th layer of atmosphere

Answer 5

Thermosphere
Temperature increasing with height up to 2000 degrees

Ionosphere is here - disturbed radios etc

Question 6

Altitude equal to 100hpa

Answer 6

53,000ft

Question 7

Altitude equal to 300hpa

Answer 7

30,000ft

Question 8

Altitude equal to 500hpa

Answer 8

18,000ft

Question 9

Altitude equal to 700hpa

Answer 9

10,000ft

Question 10

25% of density altitude

Answer 10

40,000ft

0..302kg/m3

Question 11

50% of density altitude

Answer 11

22,000ft

0.609kg/m3

Question 12

How is surface temperature measured

Answer 12

Stevenson Screen 4ft above surface

Question 13

Advantages of cruising in the stratosphere

Answer 13

Economic fuel consumption
Better TAS
Fewer clouds
Less turbulence

Question 14

Ozone

Answer 14

Found 90% in stratosphere
10% is in the troposphere

Therefore harmful at jet cruising levels