Chapter 8.2 - Atmospheric Fundamentals

Question 1

Name the two main atmosphere layers?

Answer 1

• Troposphere.

- Stratosphere.

Question 2

Which atmosphere contains most of the weather?

Answer 2

Troposphere.

Question 3

What happens with temperature in the Troposphere?

Answer 3

As height increases, temperature decreases.

Question 4

What happens with temperature in the Stratosphere?

Answer 4

In the lower section, temperature remains close to constant.

Question 5

What’s the name of the boundary between the Troposphere and the Stratosphere?

Answer 5

Tropopause.

Question 6

What is the average height of the Troposphere?

Answer 6

36 000ft.

Question 7

True or False. The Troposphere is equal size around the earth?

Answer 7

False. The Troposphere is smaller around the Equator than the North/South Poles.

Question 8

True or False. The Troposphere contains all water vapour in the atmosphere?

Answer 8

True.

Question 9

What does ELR stand for?

Answer 9

Environmental Lapse Rate.

Question 10

Under average conditions where the temperature at sea level is 15°C, at what altitude will the air freeze (0°C)?

Answer 10

7500ft.

Question 11

What does ISA stand for?

Answer 11

International Standard Atmosphere.

Question 12

What is the ISA MSL Pressure?

Answer 12

1013 hPa.

Question 13

What is the ISA MSL Temperature?

Answer 13

+15°C.

Question 14

What is the ISA Pressure Lapse Rate (2)?

Answer 14

• 30 hPa per 1000ft.

- 1 hPa per 30ft.

Question 15

What is the ISA Temperature Lapse Rate?

Answer 15

-2°C per 1000ft.

Question 16

Name four ways heat transfer within the atmosphere?

Answer 16

• Radiation.
• Conduction.
• Convection.
• Advection.

Question 17

The transfer of heat energy through space by electromagnetic waves from a hot body/substance to a cold body/substance is called what?

Answer 17

Radiation.

Question 18

The transfer of heat energy through contact from a hot body/substance to a cold body/substance is called what?

Answer 18

Conduction.

Question 19

The transfer of heat energy within a fluid (air) by movement of the fluid (air) itself is called what?

Answer 19

Convection.

Question 20

What is the method where heat (energy) is transferred within the atmosphere by vertical movement of heated air?

Answer 20

Convection.

Question 21

Name two types of weather phenomenon which are caused by Convection?

Answer 21

• Turbulence.

- Cloud Formation/Rain.

Question 22

What is the method where heat (energy) is transferred within the atmosphere by horizontal movement of heated air?

Answer 22

Advection.

Question 23

Name two types of weather phenomenon which are caused by Advection?

Answer 23

• Types of Cloud.

- Fog.

Question 24

The heat required to change states of matter from Solid to Liquid to Gas (and vice versa) with a constant temperature is called what?

Answer 24

Latent Heat.

Question 25

What is the name given to the process where a matter changes from Liquid to Gas?

Answer 25

Evaporation.

Question 26

What is the name given to the process where a matter changes from Gas to Liquid?

Answer 26

Condensation.

Question 27

What is the name given to the process where a matter changes from Liquid to Solid?

Answer 27

Freezing.

Question 28

What is the name given to the process where a matter changes from Solid to Liquid?

Answer 28

Melting.

Question 29

What’s the term called when temperature increases as height increases?

Answer 29

Temperature Inversion.

Question 30

Surface temperatures are at a minimum just after which period of the day?

Answer 30

Dawn.

Question 31

Surface temperatures are at a maximum at about which period of the day?

Answer 31

1500 LMT.

Question 32

What is a dry-bulb thermometer used for?

Answer 32

To measure ordinary air temperature.

Question 33

What is a wet-bulb thermometer used for?

Answer 33

To measure the amount of water vapour in the air.

Question 34

If humidity is high, what will the evaporation and temperature drop be?

Answer 34

Low.

Question 35

If humidity is low, what will the evaporation and temperature drop be?

Answer 35

High.

Question 36

The difference between the wet-bulb and dry-bulb temperature will give you the measurement of what?

Answer 36

Humidity in the air.

Question 37

When will the wet-bulb, dry-bulb and dew point temperature be equal?

Answer 37

If the relative humidity is close to 100%.

Question 38

True or False. The dry-bulb temperature is also used to measure the temperature of the air surrounding an Aircraft?

Answer 38

True.

Question 39

Atmospheric pressure at MSL is 1013 hPa which is equivalent to how many centimetres of mercury?

Answer 39

76.

Question 40

When two places have different MSL pressures, the pressure difference between them is known as what?

Answer 40

Horizontal Pressure Gradient.

Question 41

When QNH is set of the pressure-setting subscale of an Altimeter, this will indicate what?

Answer 41

Altitude.

Question 42

When an Aircraft is on the ground, the QNH can be found by setting the Altimeter to read what?

Answer 42

Elevation of the aerodrome.

Question 43

How does wind affect the rate of evaporation?

Answer 43

The stronger the wind, the higher the rate of evaporation.

Question 44

What is Saturated Air?

Answer 44

When the air contains the maximum amount of water vapour at a given temperature.

Question 45

Relative Humidity is expressed as what?

Answer 45

Percentage (%).

Question 46

Relative Humidity is the ratio between what?

Answer 46

Amount of water vapour in the air to the maximum amount of water vapour the air can hold at that temperature.

Question 47

For cloud to form, condensation must occur, for condensation to occur, the relative humidity must be what?

Answer 47

100%.

Question 48

Define Dew-point Temperature?

Answer 48

The temperature at which the air can no longer hold all water vapour.

Question 49

The Dew-point Temperature is a common indicator of what?

Answer 49

Atmospheric Moisture/Humidity.

Question 50

Why is the Dew-point Temperature extremely important in aviation meteorology?

Answer 50

It is the best indicator for fog formation and the height of clouds to form.

Question 51

If temperature is constant, what will happen to density and pressure?

Answer 51

Density will increase as the pressure increases.

Question 52

If pressure is constant, what will happen to density and temperature?

Answer 52

Density will decrease as the temperature increases.