11 - Meteorology 1

0.0(0)
studied byStudied by 0 people
learnLearn
examPractice Test
spaced repetitionSpaced Repetition
heart puzzleMatch
flashcardsFlashcards
Get a hint
Hint

The atmosphere is composed, in order from least to greatest, of

Get a hint
Hint

carbon dioxide, oxygen and nitrogen.

Get a hint
Hint

Water vapour is found in which layer of Earth's atmosphere?

Get a hint
Hint

Troposphere

Card Sorting

1/73

encourage image

There's no tags or description

Looks like no tags are added yet.

Study Analytics
Name
Mastery
Learn
Test
Matching
Spaced

No study sessions yet.

74 Terms

1
New cards

The atmosphere is composed, in order from least to greatest, of

carbon dioxide, oxygen and nitrogen.

2
New cards

Water vapour is found in which layer of Earth's atmosphere?

Troposphere

3
New cards

The atmospheric layers in order from the most dense to the least dense are


Troposphere, Stratosphere, Mesosphere, and Thermosphere.

4
New cards

With an elevation of 500 feet ASL and a surface temperature of 15°C. The expected temperature at 6 500 feet ASL would be

6 500 ft - 500 ft = 6 000 ft altitude change
6 x 1.98°C = 11.88°C
15°C - 11.88°C = 3.12°C

The correct answer is: 3°C.

5
New cards

What defines the start of the Tropopause?

Sudden change in lapse rate.

6
New cards

The air temperature in the Stratosphere does what with altitude

increases with altitude

7
New cards

The uniform temperature throughout the Stratosphere is

FALSE → temp in stratosphere is not uniform, it increases

8
New cards

Most weather is prevented from rising through the atmospheric layers by the

Tropopause

9
New cards

The Mesosphere is characterized by

very low temperatures.

10
New cards

The Thermosphere is characterized by

very high temperatures.

11
New cards

What percentage of Earth's atmosphere is composed of water vapour?

Less than 1 %

12
New cards

The expected temperature at 3 000 feet ASL in standard atmospheric conditions would be

15°C at sea level - (1.98°C / 1 000 ft x 3 000 ft) = 9.06°C

The correct answer is: 9°C.

13
New cards

Barometric altimeters are calibrated to react to temperature variations according to

standard atmospheric conditions

14
New cards

In the Northern Hemisphere the height of the Tropopause

decreases from Equator to the north Pole.

15
New cards

In the Northern Hemisphere the height of the Tropopause

decreases from Equator to the north Pole.

16
New cards

The ozone layer is located in the

stratosphere

17
New cards

The layer that most of the atmospheric humidity is concentrated in is the

Troposphere.

18
New cards

While at FL140 the OAT is -12°C. Under standard atmospheric conditions the expected temperature at FL110 would be

Standard temp at 11 000 feet
11 x 1.98 = 21.78
15 - 21.78 = -6.78 (-7)

The correct answer is: -7°C.

19
New cards

The boundary layer between Troposphere and the Stratosphere is known as the

Tropopause.

20
New cards

The correct composition of the atmosphere by volume is

21% oxygen and 78% nitrogen.

21
New cards

The thickness of the Troposphere varies with

Parallels of Latitude.

22
New cards

The ICAO standard atmosphere temperature at 9,500 feet is closest to

-4 dec C

23
New cards

The percentage concentration of gases in the atmosphere is constant from the surface to altitude with the exception of

water vapour.

24
New cards

Concerning the conditions in the lower part of the atmosphere it is correct that it is lower

the Tropopause is lower during the winter than in summer.

25
New cards

During cruise at FL200 the OAT is -35°C. The air mass therefore has an average temperature which is

Standard temperature is 15°C at sea level.
Therefore with a lapse rate of approx 2°C /1 000 feet
20 x 2° = 40°
15° - 40° = -25°
Standard temp at FL200 would be -25°

The correct answer is: 10°C colder than ISA.

26
New cards

The troposphere vertical extent is greater where

has a greater vertical extent above the Equator than above the Poles.

27
New cards

The pressure in the Stratosphere decreases with ______

decreases with height.

28
New cards

The feature that is associated with the Tropopause is

the abrupt change of lapse rate.

29
New cards

The Tropopause sits at approximately . . . . . feet over the Equator and at . . . . . feet over the Poles.

54 000, 25 000

30
New cards

29.92 in Hg is equivalent to how many millibars of pressure?

1013.25 millibars

31
New cards

According to standard atmosphere the station pressure as measured by two stations in the same region but at different altitudes will be

Air gets thinner as altitude increases. So a station at a lower altitude than another will have a higher pressure given matching conditions. This is the case in this question by stating that standard conditions apply, so the station that is higher is in thinner air so lower pressure and higher pressure at the lower station.

The correct answer is: higher as measured by the lower station.

32
New cards

In a high pressure system, the general movement of air may be explained as ______ and _______

diverging and descending.

33
New cards

According to the properties of standard atmosphere a station registering 28.00 in Hg at 2 000 feet elevation would report an altimeter setting of

30.00 in Hg.

1 in Hg = 1 000 feet
2 000 / 1 000 = 2 in Hg
28 + 2 = 30 in Hg

The correct answer is: 30.00 in Hg.

34
New cards

Anticyclonic pressure systems in the Northern hemisphere represent


sinking air that is rotating clockwise and flowing outward from the center.

35
New cards

Cyclonic pressure systems in the Southern Hemisphere represent

rising air that is rotating clockwise and flowing inwards towards the center

36
New cards

Which weather map symbol represents a high pressure ridge?

crisscross pattern /\/\/\/\/\/\/\/\/\/\/\/\/\/\/\

37
New cards

Precipitation is more readily associated with which weather system? (cyclonic or anticyclonic)

cyclonic

38
New cards

Lines joining areas of equal pressure are called . . . . . and are separated by . . . . . millibars.

isobars, 4

39
New cards

The indicated altitude is 8 500 feet with an altimeter setting of 29.42 in Hg. The pressure altitude would be

Select one:

a.8 000 feet.

b.8 500 feet.

c.9 000 feet.

d. 8 450 feet.

29.92 in Hg - 29.42 in Hg = 0.5 x 1 000 = 500 feet + 8 500 feet = 9 000 feet

The altimeter compares the difference between actual atmospheric pressure and the pre-selected pressure value in the Kollsman window (in this case 29.42) and converts this difference into an altitude. 29.42 is closer to the atmospheric pressure flying in 8 500 feet than 29.92, therefore a lower altitude than the Pressure Altitude is being indicated.

The correct answer is: 9 000 feet.

40
New cards

Aircraft performance is best predicated by the

Select one:

Density altitude

41
New cards

Altimeters that are in error by more than . . . . . feet when given a correct altimeter setting must be re-calibrated.

50 ft

42
New cards

After a cold front has moved in the colder air causes the air pressure to increase resulting in a slightly higher altimeter setting. T/F


True, altitude corrections should be made to obstacle clearance altitudes when temperature is 0°C or below.

43
New cards

The conditions that would be the safest to ensure that a flight level clears all the obstacles by the greatest margin would be a

If you go from high to low look out below. Altimeter is set too high the aircraft will be lower than indicated.

But in this question it is stating the reverse in the answer. Low to high. So the aircraft will be higher than indicated. If the altimeter setting was 28.72 (29.92 used in the question) and the area flown into had a higher setting, than as you reset the altimeter it would increase showing the aircraft is flying too high (better obstacle clearance).

The correct answer is: temperature more than or equal to ISA and an altimeter setting greater than 29.92 in Hg.

44
New cards

An aircraft is flying at FL180 in the Northern Hemisphere with a crosswind from the left. It is correct concerning true altitude that

Select one:

a without knowing temperatures at FL180 this question cannot be answered.

b. it decreases.

c. it remains constant.

d. it increases.

True altitude is the actual height above sea level. This altitude changes based on changes in temperature and or pressure. In this question the pressure is changing. Because the crosswind is from the left the aircraft is approaching a low pressure system. As the pressure decreases (no change to the altimeter setting is made) the indicated altitude would increase if the true altitude is maintained. If indicated altitude is maintained then the true altitude would decrease.

IT DECREASES

45
New cards

Which condition would cause the altimeter to indicate a lower altitude than that actually flown?

Air temperature higher than standard.

46
New cards
  1. Decreasing air pressure

  2. Increasing air pressure

  3. Decreasing temperature

  4. Increasing temperature

The factors that increase density altitude for a given aerodrome are:

Decreasing air pressure and increasing temperature

47
New cards

Flying over mountains with a temperature of 24ºC and the altimeter setting of 30.22 in Hg received from a nearby airfield. The terrain below the aircraft rises to 4 000 feet ASL, the true altitude when reaching 6 000 feet ASL will be

Pressure Altitude = 5 700 feet (29.92 - 30.22 =  - 0.3 x 1 000 = - 300 + 6 000 feet =)
Temperature is 24ºC
Using the E6B correct altitude of 2 000 feet AGL (= IALT 6 000 - Elev 4 000), will get 2 145 feet and add to 4 000 feet ASL
Air temperature has influence on true altitude depending on height of column of air above the ground level
The solution is 6 145 feet

Math version.

The aircraft is 2 000 feet above the terrain (indicated altitude 6 000 feet - terrain 4 000 feet)
2 x 4 (feet/1 000) = 8
8 x +21 (degrees above standard) = 168
2 000 + 168 = 2 168 feet AGL + 4 000 feet elev = true altitude of 6 168 feet ASL

Do not correct the elevation for non-standard conditions.

The correct answer is: 6 145 feet.

48
New cards

An aircraft takes off from Doha, field elevation 30 feet ASL, with the altimeter setting of 30.12 in Hg set on the altimeter. The aircraft then lands at Al Ain, field elevation 500 feet ASL, but without re-setting the altimeter sub-scale. If the altimeter setting at Al Ain at the time of landing is 29.98 in Hg the aircraft's altimeter read on touch-down

The difference between 30.12 in Hg and 29.98 in Hg results in a 140 feet difference.
Since the reference is still set to the higher air pressure, lower altitude, this difference needs to be added to the elevation.

The correct answer is: 640 feet.

49
New cards

Flying at FL220 in an air mass which is 15°C colder than ISA with the local altimeter setting of 29.02 in Hg. What would be the true height over terrain that is at 7 000 feet?

Because it is stated as FL220 that means a pressure altitude of 22 000 feet. Altimeter is set to 29.92 in Hg.

Find what the altimeter would indicate when set to 29.02 in Hg. Because it is lower when you mechanically turn the setting down the altitude decreases. in this case 900 feet.

29.92 - 29.02 = 0.9 x 1 000 = 900 feet 
Because the Pressure Level 29.02 is at a higher altitude than the Pressure Level 29.92, we have to subtract the 900 feet from PA to get Indicated Altitude (turning subscale down). 
22 000 - 900 = 21 100 feet 
The altimeter set to the current altimeter setting would indicate 21 100 feet.

To find out standard temperature at 22 000 feet calculate 
15°C - (22 x 2°C) = -29°C 
Actual outside temperature is 15°C colder than standard, therefore -29 - 15 = -44°C

Refer to E6B given: PA 22 000 feet; Temp -44°C; 
Find 14 100 feet (= 21 100 - 7 000 = indicated/calibrated altitude AGL, this represents the "column of air" above elevation) on inner scale. 
Read True height AGL on outer scale = 13 200 feet
If were asked 13 200 + 7 000 Elevation = 20 200 feet ASL (this is the true altitude)

NOTE:
When an aircraft is operating in the standard pressure region with standard pressure set on the altimeter subscale, the term “flight level” is used in lieu of “altitude” to express its height. Flight level is always expressed in hundreds of feet. For example FL 250 represents an altimeter indication of 25 000 feet; FL 50, an indication of 5 000 feet.

The correct answer is: 13 200 feet

50
New cards

During a flight over the sea at FL135 the true altitude is 13 500 feet ASL with a local altimeter setting of 30.08 in Hg. What is known about the air mass in which the aircraft is flying?

L135 implies that the altimeter setting is 29.92 in Hg. The pressure altitude is 13 500 feet.

Local altimeter setting is 30.08 in Hg

From above information we can calculate the indicated altitude.
29.92 - 30.08 = - 0.16 x 1 000 = -160 feet Working backwards to get indicated not PA so add
13 500 feet + 160 = 13 660 feet indicated

Since the true altitude is lower, the indicated is higher, the temperature must be below or colder than ISA.

The term flight level (FL) is used when the altimeter setting is 29.92 in Hg. Flight levels are used in high level airspace at 18 000 feet ASL and above, and in Northern Domestic Airspace from the surface up when in cruise.

On the E6B if you line up the true altitude on the outside scale with the indicated/calibrated altitude on the middle scale you will see that in the altitude calculations window that PA of 13 500 lines up near to -12 C, standard temp at 13 500 feet (13.5 x 2/1000 = 27 from 15 = -12). Now if you apply the altimeter setting to the indicated/calibrated. Higher setting means higher altitude shown, so 13 660 feet. And you align that indicated/calibrated altitude to the true 13 500 feet on the outside scale. You will notice that the temperature is colder than standard. Not by much.

The correct answer is: The air mass is colder than ISA.

51
New cards

An aerodrome at 984 feet ASL has an altimeter setting of 30.54 in Hg at standard temperature. If the temperature dropped 12.5°C the station pressure most likely would be

Station pressure is the pressure for that elevation (elevation does not change). When temperature decreases the pressure levels change their spacing, move closer together (air is contracting). Since the pressure level height drops but elevation stays constant that means that the elevation is now in a lower pressure.

The altimeter shows pressure level and indicates it by height above sea level. When doing circuits a pilots flies the indicated altitude for the circuit height. In the winter the circuit height AGL is a lot lower even though the altimeter is still indicating circuit height. The colder air has brought the pressure level down, which the aircraft is flying, but the elevation has not changed so the aircraft is now closer to the surface. If the pilot were to climb to the same height AGL as in the summer the altitude on the altimeter would read higher than circuit height, because the pressure dropped.

The correct answer is: less than 30.54 in Hg.

52
New cards

An aircraft is flying around the Alps at the same level as the summit on a hot day. The altimeter would indicate

a lower altitude than the summit.

53
New cards

An inversion is characterized by

an increasing temperature with increasing altitude

54
New cards

A significant inversion at low height is a characteristic of

nocturnal radiation.

55
New cards

A condition that is present when a local parcel of air is stable is

Stable air is associated with an inversion, thus heating of the stable air mass does not result in convection (vertical movement), until heated above the temperature of the inversion - at this point the air mass becomes unstable.

The correct answer is: that the parcel of air resists convection.

56
New cards

The radiation of the sun heats the

surface of Earth which then heats the air in the troposphere.

57
New cards

The stability of the atmosphere can be determined by the

ambient temperature lapse rate.

58
New cards

Horizontal differences in the mean temperature of a layer are caused by

differential heating of Earth's surface.

59
New cards

Convective activity over land in the mid-latitudes is greatest in the


summer during the afternoon.

60
New cards

How does temperature vary with increasing altitude in the ICAO standard atmosphere below the Tropopause?

Decreases

61
New cards

An inversion is

an increase of temperature with height.

62
New cards

An isothermal layer is a layer of air in which the temperature

remains constant with height.

63
New cards

A common cause of a ground or surface based temperature inversion is

terrestrial radiation on a clear night with no or very light winds.

64
New cards

The environmental lapse rate in the real atmosphere

varies with time. It is not fixed

65
New cards

Diurnal variation refers to

temperature variation by day and night.

66
New cards

A common location for an inversion is


in the Stratosphere.

Tropopause is an isothermal layer, temperature remains the same with an increase in height. The change in lapse rate (decrease in temp) to isothermal (constant temp) is how the tropopause is found.

Wake turbulence would create colder air on top and warmer air on the bottom, the rising air would expand and cool and the subsiding are would be compressed and warmed.

Cumulus cloud base forms when the temperature cools to the dew point as the air rises, convection, and cools.

67
New cards

A characteristic associated with a temperature inversion is

stability.

68
New cards

Which statement regarding heat distribution is false?

Heating variation is fairly uniform throughout most land areas.

69
New cards

The heat of the Earth is transferred upwards largely by

Radiation does transfer heat upwards but convection is what takes the heat to the higher levels. Radiation is only low level.

The correct answer is: convection.

70
New cards

The incoming . . . . . radiation from the sun's rays are re-radiated into the atmosphere as infrared radiation which has a . . . . . wavelength than the incoming solar radiation.

shortwave, longer

71
New cards

Advection is the

horizontal motion of air.

72
New cards

Variations in heating of the atmosphere with respect to seasons is caused by the


tilt of Earth's axis.

73
New cards

Convert 30°F into Celsius.


-1°C

74
New cards

Not a means of cooling the atmosphere is

Adiabatic refers to a parcel of air that is not affected (in temperature or moisture) by the surrounding air. So as a parcel rises or falls the change in temperature is only caused by expanding (cooling) or contracting (warming).

Radiation (ground warming or cooling air) and advection (horizontal movement of air over warmer or cooler ground) both can warm and cool the atmosphere.

Where as Convection is rising air. As air rises it will expand and cool but it will still be warmer than the surrounding air. Which means it will be adding heat to the higher levels of the atmosphere, not cooling it.

The correct answer is: convection.