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PPL Course - (3) Navigation and Meteorology > Chapter 8.3 - Stability, Clouds and Precipitation > Flashcards

Chapter 8.3 - Stability, Clouds and Precipitation Flashcards

1
Q

What is defined as a stable atmosphere?

A

A parcel of air moving upwards returns to its original position.

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2
Q

What is defined as an unstable atmosphere?

A

A parcel of air moving upwards continues to rise rather than return to its original position.

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3
Q

What is defined as a neutrally stable atmosphere?

A

A parcel of air which remains displaced.

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4
Q

What is defined as adiabatic cooling?

A

A parcel of air which is cooled by the decrease in pressure, assuming no other heat energy is transferred.

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5
Q

What does DALR stand for?

A

Dry Adiabatic Lapse Rate.

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6
Q

Define DALR?

A

The rate at which the temperature of unsaturated air changes through the atmosphere.

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7
Q

What is the DALR?

A

-3°C per 1000ft.

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8
Q

What does SALR stand for?

A

Saturated Adiabatic Lapse Rate.

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9
Q

Define SALR?

A

The rate at which the temperature of saturated air changes through the atmosphere.

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10
Q

What is the SALR?

A

-1.5°C per 1000ft.

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11
Q

Stable air occurs when ELR is?

A

Less than the SALR.

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12
Q

Name two effects of a stable atmosphere?

A
  • Stratiform clouds.

- Poor visibility.

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13
Q

Unstable air occurs when ELR is?

A

Higher than the DALR.

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14
Q

Name two effects of a stable atmosphere?

A
  • Cumuliform clouds.

- Good visibility.

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15
Q

If the ELR falls between the SALR and DALR what factor is dependent in understanding the stability of the atmosphere?

A

Humidity.

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16
Q

True or False. The temperature lapse rate in the atmosphere varies depending on the surface?

A

True.

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17
Q

What is defined as a surface/radiation inversion layer?

A

When the air adjacent to the surface becomes colder than the air above.

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18
Q

What is defined as a turbulence inversion layer?

A

When dry air within a thin layer close to the ground is mixed by turbulence.

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19
Q

What is defined as a frontal inversion layer?

A

When two air masses of different temperatures meet, the cool air forces the warmer air aloft.

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20
Q

When will a frontal layer occur?

A

At the boundary between two air masses.

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21
Q

A subsidence inversion layer is associated with which weather phenomenon?

A

Anticyclone/High Pressure.

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22
Q

What effect would a decrease in density (when ascending through an inversion layer) have on an Aircraft?

A

Loss in lift and power.

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23
Q

What effect would a decrease in density (when ascending through an inversion layer) have on flight instruments?

A

The Airspeed Indicator will fluctuate.

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24
Q

True or False. A decrease in density (when ascending through an inversion layer) will have a major effect on the operation of an Aircraft?

A

False.

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25
True or False. Reduced visibility can effect an inversion layer?
False. It affects the layer below.
26
What type of flights are affected by reduced visibility below an inversion?
Visual Flights.
27
True or False. Turbulence exists in an inversion layer?
False. As inversion layers are stable.
28
An Aircraft climbing/descending through an inversion layer will be subjected to an alteration in what?
Drift.
29
What the two main classifications of clouds?
- Cumuliform. | - Stratiform.
30
Name three cloud groups and their height?
- Low Cloud = surface to 8500ft. - Medium Cloud = 8500ft to 20 000ft. - High Cloud = 20 000ft and above.
31
What is the abbreviation and base of Stratus clouds?
- ST. | - Base = 500/2000ft.
32
What is the abbreviation and base of Stratocumulus clouds?
- SC. | - Base = 2000/5000ft.
33
What is the abbreviation and base of Cumulonimbus clouds?
- CB. | - Base = 2000/5000ft.
34
What is the abbreviation and base of Towering Cumulus clouds?
- TCU. | - Base = 2000/5000ft.
35
What is the abbreviation and base of Cumulus clouds?
- CU. | - Base = 2000/5000ft.
36
What is the abbreviation and base of Altocumulus clouds?
- AC. | - Base = 8500/20 000ft.
37
What is the abbreviation and base of Altostratus clouds?
- AS. | - Base = 8500/20 000ft.
38
What is the abbreviation and base of Nimbostratus clouds?
- NS. | - Base = 500/8500ft.
39
What is the abbreviation and thickness of Cirrocumulus clouds?
- CC. | - Usually only a thin layer.
40
What is the abbreviation and thickness of Cirrostratus clouds?
- CS. | - Usually only a thin layer.
41
What is the abbreviation and thickness of Cirrus clouds?
- CI. | - Usually only a thin layer.
42
How many OKTAs are there in SKC?
0.
43
How many OKTAs are there in FEW?
1-2.
44
How many OKTAs are there in SCT?
3-4.
45
How many OKTAs are there in BKN?
5-7.
46
How many OKTAs are there in OVC?
8.
47
Cumuliform clouds have a large (horizontal/vertical) extent?
Vertical.
48
Stratiform clouds have a large (horizontal/vertical) extent?
Horizontal.
49
Cumulonimbus clouds: Description?
Heavy and Dense.
50
Cumulonimbus clouds: Process of Formation?
Convection.
51
Cumulonimbus clouds (Flying Conditions): Weather (2)?
- Thunderstorms/Lighting. | - Moderate/Heavy Showers.
52
Cumulonimbus clouds (Flying Conditions): Turbulence?
Severe.
53
Cumulonimbus clouds (Flying Conditions): Visibility?
Less than 20m.
54
Cumulonimbus clouds (Flying Conditions): Effect on VFR?
Dangerous.
55
True or False. Cumulonimbus is one of the most dangerous clouds?
True.
56
Cumulus/Towering Cumulus clouds: Description?
Detached clouds.
57
Cumulus/Towering Cumulus clouds: Process of Formation?
Convection.
58
Cumulus/Towering Cumulus (Flying Conditions): Weather (2)?
- CU = Nil. | - TCU = Moderate/Heavy Showers.
59
Cumulus/Towering Cumulus (Flying Conditions): Turbulence (2)?
- CU = Light to Moderate. | - TCU = Moderate to Severe.
60
Cumulus/Towering Cumulus (Flying Conditions): Visibility?
0 to 200m.
61
Cumulus/Towering Cumulus (Flying Conditions): Effect on VFR?
Nil.
62
Stratocumulus clouds: Description?
Grey/Whitish Patch/Sheet clouds.
63
Stratocumulus clouds: Process of Formation?
Turbulence.
64
Stratocumulus clouds (Flying Conditions): Weather?
Nil but can produce drizzle.
65
Stratocumulus clouds (Flying Conditions): Turbulence?
Light to Moderate.
66
Stratocumulus clouds (Flying Conditions): Visibility?
30 to 200m.
67
Stratocumulus clouds (Flying Conditions): Effect on VFR?
Significant.
68
Stratus clouds: Description?
Grey clouds.
69
Grey clouds.
Turbulence.
70
Stratus clouds (Flying Conditions): Weather?
Occasional Drizzle.
71
Stratus clouds (Flying Conditions): Turbulence?
Nil to Light.
72
Stratus clouds (Flying Conditions): Visibility?
10 to 200m.
73
Stratus clouds (Flying Conditions): Effect on VFR?
Dangerous.
74
Altostratus clouds: Description?
Greyish/Bluish clouds.
75
Altostratus clouds: Process of Formation?
Widespread ascent and frontal lifting.
76
Altostratus clouds (Flying Conditions): Weather (2)?
- Thin AS = Generally nil, can produce light rain in Virga. | - Thick AS = Can produce light, intermittent/continuous rain.
77
Altostratus clouds (Flying Conditions): Turbulence (2)?
- Thin AS = Nil to Light. | - Thick AS = Can be Moderate.
78
Altostratus clouds (Flying Conditions): Visibility?
300 to 1000m.
79
Altostratus clouds (Flying Conditions): Effect on VFR?
None.
80
Altocumulus clouds: Description?
Layer/Patches of cloud.
81
Altocumulus clouds: Process of Formation?
Turbulence and Convection.
82
Altocumulus clouds (Flying Conditions): Weather?
Nil.
83
Altocumulus clouds (Flying Conditions): Turbulence?
Light.
84
Altocumulus clouds (Flying Conditions): Visibility?
500m.
85
Altocumulus clouds (Flying Conditions): Effect on VFR?
None.
86
Nimbostratus clouds: Description?
Dark grey cloud covering the whole sky.
87
Nimbostratus clouds: Process of Formation?
Widespread ascent and frontal lifting.
88
Nimbostratus clouds (Flying Conditions): Weather?
Moderate/Heavy continuous rain.
89
Nimbostratus clouds (Flying Conditions): Turbulence?
Nil/Light
90
Nimbostratus clouds (Flying Conditions): Visibility?
20 to 100m
91
Nimbostratus clouds (Flying Conditions): Effect on VFR?
Significant/Dangerous.
92
True or False. Nimbostratus clouds are the only clouds to produce continuous rain?
True.
93
Cirrocumulus clouds: Description?
Thin, white patch/sheet/layer of cloud.
94
Cirrocumulus clouds: Process of Formation?
Turbulence.
95
Cirrocumulus clouds (Flying Conditions): Weather?
Nil.
96
Cirrocumulus clouds (Flying Conditions): Turbulence?
Nil to Light.
97
Cirrocumulus clouds (Flying Conditions): Visibility?
1000m.
98
Cirrocumulus clouds (Flying Conditions): Effect on VFR?
None.
99
Cirrostratus clouds: Description?
Transparent whitish veil.
100
Cirrostratus clouds: Process of Formation?
Widespread ascent and frontal lifting.
101
Cirrostratus clouds (Flying Conditions): Weather?
Nil.
102
Cirrostratus clouds (Flying Conditions): Turbulence?
Nil to Light.
103
Cirrostratus clouds (Flying Conditions): Visibility?
Over 1000m.
104
Cirrostratus clouds (Flying Conditions): Effect on VFR?
None.
105
Cirrus clouds: Description?
Cirrus clouds: Description?
106
Cirrus clouds: Process of Formation?
Widespread ascent and frontal lifting.
107
Cirrus clouds (Flying Conditions): Weather?
Nil.
108
Cirrus clouds (Flying Conditions): Turbulence?
Nil to occasionally light.
109
Cirrus clouds (Flying Conditions): Visibility?
Over 1000m.
110
Cirrus clouds (Flying Conditions): Effect on VFR?
None.
111
Define Precipitation?
Any aqueous deposit that falls to the ground.
112
Name four products of Precipitation?
- Rain. - Drizzle. - Snow. - Hail.
113
Name three classifications of Precipitation?
- Showers. - Intermittent Precipitation. - Continuous Precipitation.
114
Which clouds are associated with Shower Precipitation (2)?
- Cumulonimbus. | - Cumulus.
115
How long does Shower Precipitation last for?
15 to 30 minutes.
116
Which clouds are associated with Intermittent Precipitation?
Stratiform.
117
How long does Intermittent Precipitation last for?
Up to several hours.
118
Which cloud is associated with Continuous Precipitation?
Nimbostratus.
119
How long does Continuous Precipitation last for?
Several hours or more.

PPL Course - (3) Navigation and Meteorology (23 decks)

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