Ch 1 - The Atmosphere

Question 1

Composition

Answer 1

78% Nitrogen
21% Oxygen
0.93% Argon
0.038% Carbon Dioxide
0.0407% Others

1% Water Vapour (0-5%)

Question 2

Troposphere

Answer 2

0-11km (36,090ft) 
75% Total Mass of Air 
90% of the Water Vapour 
Lapse Rate -1.98 degrees C/1000ft
Where all of our weather is

Question 3

Tropopause

Answer 3

11km Average at 45-50degrees N and S

Boundary Layer between tropopause and stratosphere

Height varies around the earth:

• 8-10km Poles -40 - -50 degrees C
• 16-18km roughly -75 degrees C

Season:

• Summer, height increases slightly
• Winter, height decreases slightly

Breaks and folds due to different air masses meeting

Question 4

Stratosphere

Answer 4

11km - roughly 50km

Temp stays constant between 11-20km (65,600ft) at -56.5 degrees C (Isothermal Layer)
Lapse rate of +0.3 degrees C per 1000ft 20-50km Inversion

Ozone Layer is found in the stratosphere (roughly 25km above surface)
- Absorbs and filters uv light and absorbs heat (hence temp rise above it)

Question 5

Stratopause

Answer 5

Roughly 50km above GL
Boundary between stratosphere and mesosphere
Average temp is 0 degrees C

Question 6

Mesosphere

Answer 6

50-80/90km
Temp decreases
- lapse rate roughly -2.5 degrees C / 1000ft

Question 7

Mesopause

Answer 7

Roughly -90 degrees C

Question 8

Thermosphere (Ionosphere)

Answer 8

80/90 - 700km

Then Exosphere, edge of space, where temp increases rapidly

Question 9

ISA

Answer 9

Temperature 15 degrees C
Pressure 1013.25hPa or 29.92 inHg or 760mmHg
Density 1.225kg/metre cubed
Lapse Rate -1.98 degrees C / 1000ft

Question 10

ISA Deviations

Answer 10

ISA = 15 - ((alt. / 1000)x2)

Deviation = difference between ISA and OAT