2021 Meteorology Flashcards
(106 cards)
1
Q
Composition of the atmosphere:
A
Nitrogen - 78%
Oxygen - 21%
Water Vapor - 0-3%
Carbon Dioxide - 0.03%
Argon, helium, ozone, helium, other rare gasses
2
Q
What is the latent heat of fusion?
A
Freezing and melting.
freeze & fuze
3
Q
What is latent heat of vaporization?
A
Condensation and evaporation.
4
Q
What is latent heat of sublimation?
A
Sublimation & deposition between a gas and a solid.
5
Q
What is condensation?
A
When water vapor changing from a gaseous state to a liquid state.
Latent heat is RELEASED.
6
Q
What is evaporation?
A
When water vapor changing from a liquid state into a gaseous state.
7
Q
What is sublimation?
A
When water vapor changes from a gaseous state to a solid state or vice versa.
Remember, sublimation is the weird one. Gas to a solid or solid to a gas? that’s weird.
8
Q
When water vapor changes into a liquid, is energy (heat) absorbed or released?
A
Energy (heat) is released to the surrounding air.
9
Q
When water vapor changes into a gaseous state, is energy (heat) absorbed or released?
A
Energy (heat) is absorbed from the surrounding air.
10
Q
What is relative humidity?
A
The ratio of the amount of water vapor that exist in the air to the amount that can be held.
Water vapor that exists : Water vapor it can hold
11
Q
How is relative humidity expressed?
A
As a percentage.
12
Q
Does temperature increase or decrease with altitude in the Troposphere?
A
Decreases. (down, up, down, up)
13
Q
Does temperature increase or decrease with altitude in the Stratosphere?
A
Increases. (down, up, down, up)
14
Q
Does temperature increase or decrease with altitude in the Mesosphere?
A
Decreases. (down, up, down, up)
15
Q
Does temperature increase or decrease with altitude in the Thermosphere?
A
Increases. (down, up, down, up)
16
Q
Weather is forecasted below ____ on a GFA.
A
24,000’.
17
Q
How long are significant weather charts valid?
A
12 hours.
18
Q
When are surface analysis charts issued?
A
0600Z, 1200Z, 1800Z, 0000Z.
19
Q
Where are AWOS stations located?
A
At an aerodrome.
20
Q
What is the dry adiabatic lapse rate?
A
3 degrees per 1000ft.
Dry is the nicest and biggest. 3 degrees.
21
Q
What is the saturated adiabatic lapse rate?
A
1.5 degrees per 1000ft.
“Saturated” is a one-off! 1.5!
22
Q
What is the environmental lapse rate?
A
2 degrees per 1000ft.
Good for the environment, your favorite number, 2!
23
Q
What is MIFG on a METAR?
A
Shallow fog.
24
Q
An altimeter will ________ in higher than normal temperatures.
A
Overread.
Higher than normal temperatures, so its a higher temperature up at altitude than normal. Your plane thinks you’re closer to the ground, so your altimeter overreads!
25
How is the earth's surface heated?
Short-wave solar radiation.
"Short" wave, closer to the sun.
26
How do you calculate ISA deviation?
ISA temperature = (altitude/1000) × -2 + 15
Deviation = (actual OAT at altitude) - (ISA temperature)
27
What is overruning?
Most commonly is the process for development of freezing rain.
A weather pattern in which a relatively warm air mass is in motion above another air mass of greater density at the surface.
28
Fog, stratus clouds, drizzle, and haze is associated with:
Stable air.
Fog is good!
29
BR as reported in a METAR means what?
A cloud layer at ground level where visibility is greater than 5/8SM.
30
Which warm fronts are most common in Canada during the winter months?
Continental arctic, maritime arctic.
31
What are warm katabatic winds?
Chinooks.
32
Which cold fronts are commonly found in Canada during the Summer months?
Maritime arctic, maritime polar.
33
What is true of a microburst?
Downburst that lasts for 5 minutes with a diameter of less than 2nm.
34
An AWOS will report a max visibility of what?
9SM.
35
What type of fog forms as a result of raising the dew point to the surrounding air temperature?
Steam fog.
36
What is mean sea level pressure?
1013.25MB or 29.92"
37
What is the ICAO lapse rate?
1.98 degrees per 1,000'.
38
What is the approximate height of the Tropopause?
36,089ft.
39
What is the top of the ICAO standard atmosphere?
65,000ft.
40
What percentage of UV radiation is reflected back into space by the atmosphere (ozone)?
6%. atmopsphere is sixus.
41
What percentage of UV radiation is reflected back into space by cloud tops?
20%. 2nd biggest
42
What percentage of UV radiation is reflected back into space by earth's surface?
4%. smallest
43
What percentage of UV radiation is absorbed by the earths surface?
51%. biggest
44
What processes heat the troposphere?
Terrestrial Radiation and Conduction.
45
The amount of energy that the earth absorbs during the course of a day that radiates outwards is dependent on:
- Time of day
- Time of year
- Latitude in question
46
What is conduction heating?
A process where one object is heated or cooled by being in contact with another.
"Conductor we have a problem!" Heat TRANSFER by contact, like a train transfers.
47
What is turbulent mixing?
When wind blows over the surface of the earth, creating eddies due to friction.
48
What is convection heating?
Includes large scale ascent and descent of air masses. Also is the process where small-scale thunderstorms are produced.
As the air is warmed by the surface of the earth, the air rises, and colder, more dense air fills in beneath it.
49
What is advection heating?
The "horizontal movement" of something.
Horizontal movement of an air mass. Heating of the atmosphere can occur by advection when a cooler air mass moves over a warm surface, and warms the air by radiation and conduction.
50
What is compression heating?
When air descends from a higher altitude to a lower altitude, it is called subsidence. This air subsides into areas of higher pressure causing air to be compressed causing temperature rise.
51
How do you calculate relative humidity?
100 - 5 (temperature - dew point)
Answer is a percentage!
52
Define MSL pressure.
Station pressure reduced to MSL using the average surface temperature over the last 12 hours.
"STATION PRESSURE REDUCED TO MSL USING 12 HOURS AVERAGE TEMPERATURE"
53
How long are SIGMET charts valid for?
12 hours.
54
What is true of a macroburst?
Downburst that lasts between 5 and 20 minutes and has a diameter of MORE than 2nm.
55
Upper air analysis chart altitudes and pressures:
```
5,000 = 850mb
10,000 = 700mb
18,000 = 500mb
24,000 = 400mb
```
56
What is the process called when water vapour changes from a gas to a liquid state?
Condensation. Latent heat is released.
57
What is the process called when water vapour changes from a liquid to a gaseous state?
Evaporation. Latent heat is absorbed (steeeeam is hot; ie. latent head is absorbed)
58
What is the process called when water vapour changes from a gas to a solid state?
Sublimation. Latent heat is released.
59
What is the process called when water vapour changes from a solid to a gaseous state?
Deposition. Latent heat is absorbed.
60
What is the process called when water vapour changes from a liquid to a solid?
Freezing. Latent heat is released.
61
What is the process called when water vapour changes from a solid to a liquid?
Melting. Latent heat is absorbed.
62
What is the mb pressure at 5,000ft?
850mb.
63
What is the approximate altitude at 850mb?
5,000ft.
64
What is the mb pressure at 10,000ft?
700mb.
65
What is the approximate altitude at 700mb?
10,000ft.
66
What is the mb pressure at 18,000ft?
500mb.
67
What is the approximate altitude at 500mb?
`18,000mb.
68
What is the mb pressure at 24,000ft?
400mb.
69
What is conditional instability? Where is it found?
When the ELR is less than the DALR but greater than the SALR.
If this air is UNsaturated, it is stable. If the air is saturated, it is unstable.
70
How far apart are isobars plotted on a surface analysis chart?
Every 4mb.
71
A stratiform cloud at a warm front indicates what?
The air is moist and stable.
72
When the air is moist and stable at a warm front, what cloud could possibly form?
A stratiform cloud.
73
A cumuliform cloud forms at a warm front. What does this indicate?
The air is moist and unstable.
74
What cloud could form if the air at a warm front is moist and unstable?
Cumuliform cloud.
75
What does the term CAVOK mean?
No cloud below 5,000ft, no precipitation, no thunderstorms, no fog or drifting snow and visibility is 6 miles or more.
76
TDZE altitude formula:
Difference in altimeter settings ✕ 1000 = altitude difference
indicated altitude - altitude difference = actual altitude
actual altitude - elevation = height above TDZE
77
The distance between different vertical pressure areas are:
Less in cold air than in warm air.
Warm air is less dense, so the total air mass is higher, versus a dense, cold air mass which stays lower.
78
Where is the coldest temperature in our atmosphere?
The mesopause.
79
When are LF, MF and HF bands at their weakest?
During the period of the "dark side of sunset and sunrise"
80
Rule of thumb when attempting long range LF, MF or HF frequency communications:
Sundown - Tune down in frequency
| Sun up - Tune up in frequency
81
How much of the sun's UV radiation is absorbed by ozone?
Approximately 19%.
82
What process allows for heating of the troposphere in the higher levels?
Release of latent heat. As water is evaporated from an ocean, it absorbs latent heat. When it hits the dewpoint, it releases the latent heat; warming the air above the clouds.
83
What is an isothermal layer?
Means that the temperature if the air is not changing with a change in altitude..
84
If the environmental lapse rate is greater than the dry adiabatic lapse rate, it is considered an ______ condition.
Unstable. Greater than dry is bad!
85
If the environmental lapse rate is less than the saturated adiabatic lapse rate, it is considered an ______ condition.
Stable condition. The lapse rate is shallow; its more chill.
86
If the environmental lapse rate is greater than the saturated adiabatic lapse rate but less than the dry adiabatic lapse rate, what does this make?
This situation causes conditional instability.
ALWAYS ASSUME AN UNSTABLE CONDITION
87
The steeper the lapse rate, the more vertical development becomes possible; UNSTABLE.
To remember
88
What is an isobar?
Lines with equal pressure.
89
What is pressure gradient?
The change in distance with regards to pressure. Directly related to the spacing of isobars.
90
How is mean sea level pressure calculated?
Based upon an average temperature at a station over last 12 hours and assumes a standard lapse rate of 2 Celsius/1000'.
91
How is an altimeter setting calculated?
Based on ICAO standard temperature (15 degrees) and the standard lapse rate of 2 degrees/1000'.
92
What is diurnal effect?
As the lower atmosphere is heated by conduction and convection, the lower air rises at its warmer.
Cooler replaces it below, bringing the upper winds from above, down below, causing higher/gusty winds.
At peak effect during midday and subsides at dusk.
93
What is a low level nocturnal jet stream?
During night, an inversion can happen. The LLJ has ceased to exist near the surface, and is now existing above the inversion line. Above the inversion is less dense air where wind speeds are fast.
AT NIGHT TIME WITH INVERSIONS
94
What is an isotac?
An equiglacial line on a map or chart connecting points where ice melts at the same time in spring.
95
What does CCA or CCB It means a mean on a METAR?
It means a correction to a METAR or SPECI; CCA is first correction, then CCB is second correction, and so on.
96
What is a virga associated with?
Thunderstorms and is a sign of strong downdrafts and MICROBURSTS.
Contain shafts of precipitation or cold air.
97
Ice pellets may be found:
In a warm front during the winter.
98
At a stationary front:
Weather may deteriorate below VFR when it rains.
99
Where would an aircraft likely encounter freezing rain?
Under an approaching winter warm front.
100
What is an AWBS?
A fully interpretive weather briefing service. It is available at all Flight Information Centres (FIC) (1-866-WXBRIEF) and designated Flight Service Stations (FSS) (1-800-INFO FSS).
Aviation Weather Briefing Service! Easy.
101
What is pressure altitude?
The altitude where a given pressure is found in the standard atmosphere.
102
What can advection fog do that radiation fog cannot?
Advection fog can develop over both water and land.
Radiation fog can only occur over land.
103
What occurs when moist, stable air moves east to west over the praries?
Upslope fog, because prairies are sloping upwards.
104
Extensive fog ahead of a warm front:
Cold air is becoming saturated by evaporation of rain that falls from the warm air.
105
How are air masses categorized, what are they based on?
Air masses are categorized by their uniformity in temperature and moisture in the HORIZONTAL.
106
An arctic front would be found between:
Continental arctic & maritime arctic.
