Deck 6: Stability and Cloud Development

Question 1

Which of the following gives the height of the base of a cumulus cloud when the surface air temperature is 45°C and the dew point is 25°C?

A)1125 m
B)2000 m
C)2500 m
D)4000 m

Answer 1

C

Question 2

Which of the following pr°Cesses can generate the convective instability ass°Ciated with severe thunderstorms and tornadoes?

A)forcing a layer of moist air to descend a mountain range
B)creating shadows on the land surface
C)heating the upper portion of an unsaturated layer of air
D)lifting a stable air layer whose surface is humid and whose top is dry

Answer 2

D

Question 3

Which of the following gives the name for the rate at which the temperature changes inside a rising (or descending) parcel of moist air?

A)latent heat release rate
B)saturated adiabatic lapse rate
C)dry adiabatic lapse rate
D)environmental lapse rate

Answer 3

B

Question 4

Which of the following statements describes the pressure areas and air motions ass°Ciated with the development of subsidence inversions?

A)The pressure areas are high, and the air motions are sinking.
B)The pressure areas are low, and the air motions are rising.
C)The pressure areas are high, and the air motions are rising.
D)The pressure areas are low, and the air motions are sinking.

Question 5

Which of the following conditions in the atmosphere °Ccurs when the environmental lapse rate is less than the moist adiabatic rate?

A)neutrally stable
B)absolutely unstable
C)conditionally unstable
D)absolutely stable

Question 6

Which of the following conditions determines conditional instability?

A)wind
B)fog
C)saturation
D)low pressure

Question 7

Which of the following defines the dry adiabatic lapse rate?

A)the rate at which temperature changes in a rising or descending parcel of unsaturated air
B)the rate at which latent heat energy is released in a rising air parcel
C)the rate at which an air parcel rises
D)the rate at which volume changes when a parcel expands or is compressed

Question 8

Which of the following surface conditions produces a convective cumulus cloud with the highest base?

A)air temperature 25°C and dew point 10°C
B)air temperature 35°C and dew point 10°C
C)air temperature 40°C and dew point 30°C
D)air temperature 45°C and dew point 25°C

Question 9

Which of the following terms refers to wavelike clouds that look like water breaking along a shore?

A)cloud streets
B)mammatus clouds
C)billow clouds
D)pileus clouds

Question 10

Suppose the surface air temperature is 29C. If the base of a cumulus congestus cloud directly above you is 2000 metres, what is the approximate temperature at an altitude of 5000 metres inside the cloud? (Assume the dry adiabatic rate is 1011efbc95_3126_a591_ad5f_1348e684797a_TB1378_00C per 1000 metres, and the moist adiabatic rate is 611efbc95_3126_a591_ad5f_1348e684797a_TB1378_00C per 1000 metres)

A)-1311efbc95_3126_a591_ad5f_1348e684797a_TB1378_00C
B)-911efbc95_3126_a591_ad5f_1348e684797a_TB1378_00C
C)-811efbc95_3126_a591_ad5f_1348e684797a_TB1378_00C
D)-511efbc95_3126_a591_ad5f_1348e684797a_TB1378_00C

Question 11

Which of the following gives the air temperature at 2000 metres above the ground when the environmental lapse rate is 5C per 1000 metres and the temperature at the Earth's surface is 2511efbc95_3126_a591_ad5f_1348e684797a_TB1378_00C?

A)2011efbc95_3126_a591_ad5f_1348e684797a_TB1378_00C
B)3011efbc95_3126_a591_ad5f_1348e684797a_TB1378_00C
C)2511efbc95_3126_a591_ad5f_1348e684797a_TB1378_00C
D)1511efbc95_3126_a591_ad5f_1348e684797a_TB1378_00C

Question 12

Which of the following statements accurately compares the dry adiabatic lapse rate with the moist adiabatic lapse rate?

A)The dry adiabatic lapse rate is sometimes greater than the moist adiabatic lapse rate.
B)The dry adiabatic lapse rate is never greater than the moist adiabatic lapse rate.
C)The dry adiabatic lapse rate is always greater than the moist adiabatic lapse rate.

Question 13

Which of the following describes what happens to the dew point temperature in a rising thermal?

A)It increases at a faster rate than the parcel temperature.
B)It increases at a slower rate than the parcel temperature.
C)It decreases at the same rate as the parcel temperature.
D)It decreases at a slower rate than the parcel temperature.

Question 14

Which of the following accurately describes the relation between subsidence and stability?

A)Subsidence decreases stability.
B)Subsidence has little effect on stability.
C)Subsidence increases stability.

Question 15

Which of the following terms refers to alt°Cumulus clouds that become arranged in rows?

A)humilis
B)rotors
C)cloud streets
D)castellanus

Question 16

Which of the following terms refers to the rate at which the actual air temperature changes with increasing height above the surface?

A)moist adiabatic rate
B)environmental lapse rate
C)dry adiabatic rate
D)thermocline

Question 17

Which of the following pr°Cesses °Ccurs when a completely dry air parcel first rises and cools, and then subsequently sinks and warms?

A)an irreversible adiabatic process
B)a reversible adiabatic process
C)an irreversible pseudoadiabatic process
D)a reversible pseudoadiabatic process

Question 18

Referring to the figure below, which of the environmental temperature profiles indicates the most stable atmosphere?

A)profile A
B)profile B
C)profile C
D)profile D

Question 19

Which of the following is the name for wave clouds that often form over or downwind of a mountain?

A)castellanus clouds
B)lenticular clouds
C)nacreous clouds
D)mammatus clouds

Question 20

Which of the following pr°Cesses make a layer of air more unstable?

A)warming the upper part of the layer
B)cooling the upper part of the layer
C)preventing mixing of the air in the layer
D)sinking the entire air layer

Question 21

Which of the following conditions, working together, make the atmosphere most unstable?

A)warm surface and cool air aloft
B)cool surface and cool air aloft
C)warm surface and warm air aloft
D)cool surface and warm air aloft

Question 22

Most thunderstorms do not extend very far into the stratosphere. Which of the following conditions of the air in the stratosphere explain this fact?

A)air that is too thin
B)air that is unstable
C)air that is stable
D)air that is too cold

Question 23

Which of the following atmospheric conditions °Ccurs when an air parcel is given a small push upward and it continues to move upward on its own accord?

A)unstable
B)dynamic
C)stable
D)buoyant

Question 24

Which of the following describes what an adiabatic chart is useful for determining?

A)isobars
B)a station model
C)the wind speed
D)the lifting condensation level

Question 25

Which of the following terms refers to clouds such as alt°Cumulus and cirr°Cumulus that develop vertical, tower-like extensions?

A)castellanus
B)rotors
C)billows
D)pileus

Question 26

A parcel of unsaturated air with a temperature of 30°C rises from the surface to an altitude of 1000 metres. Which of the following describes the temperature of the unsaturated air parcel at this altitude?

A)6°C colder than at the surface
B)6°C warmer than at the surface
C)10°C colder than at the surface
D)10°C warmer than at the surface

Question 27

Which of the following names is commonly used to describe the drier region on the downwind (leeward) side of a mountain range?

A)rain shadow
B)inversion region
C)compression region
D)orographic

Question 28

Which of the following conditions, working together, make the atmosphere most stable?

A)cool surface and warm air aloft
B)warm surface and warm air aloft
C)cool surface and cool air aloft
D)warm surface and cool air aloft

Question 29

KM
Which of the following describes air that resists vertical displacement?

A)neutral
B)unstable
C)stable
D)latent

Question 30

At the Earth's surface, at which of the following temperatures does a rising saturated air parcel cool most rapidly?

A)0°C
B)10°C
C)-12°C
D)20°C

Question 31

Which of the following cloud types most likely forms in absolutely stable air?

A)stratus
B)cumulonimbus
C)cumulus congestus
D)altocumulus

Question 32

KM
A cloud must have formed at which of the following altitudes?

A)1 km
B)2 km
C)3 km
D)4 km

Question 33

Which of the following explains why there is a difference between the moist and dry adiabatic rates?

A)Latent heat is released by a rising parcel of saturated air.
B)Saturated air is always unstable.
C)An unsaturated air parcel expands more rapidly than a saturated air parcel.
D)Moist air weighs less than dry air.

Question 34

Which of the following statements describes the environmental lapse rate in a conditionally unstable atmosphere?

A)It will be less than the moist adiabatic rate and less than the dry adiabatic rate.
B)It will be greater than the moist adiabatic rate and greater than dry adiabatic rate.
C)It will be less than the moist adiabatic rate and greater than the dry adiabatic rate.
D)It will be greater than the moist adiabatic rate and less then the dry adiabatic rate.

Question 35

-Which of the following conditions is the most stable?

A)3C per km environmental lapse rate
B)isothermal conditions
C)an inversion
D)13C per km environmental lapse rate

Question 36

KM
If the environmental lapse rate in the figure above is 8°C/km, at what altitude will the air parcel become warmer than its environment?

A)1 km
B)2 km
C)3 km
D)4 km

Question 37

Which of the following is a measuring device that is used in order to produce a sounding?

A)radiosonde
B)barograph
C)psychrometre
D)thermometre

Question 38

Which of the following environmental lapse rates represents the most unstable atmosphere in a layer of unsaturated air?

A)6C per 1000 m
B)911efbc95_3126_a591_ad5f_1348e684797a_TB1378_00C per 1000 m
C)1111efbc95_3126_a591_ad5f_1348e684797a_TB1378_00C per 1000 m
D)311efbc95_3126_a591_ad5f_1348e684797a_TB1378_00C per 1000 m

Question 39

Which of the following terms applies to the vertical motion of air caused by the sun heating the ground?

A)orographic lifting
B)subsidence
C)convection
D)convergence

Question 40

KM
Which of the following gives an example of orographic clouds?

A)clouds forming over a warm ocean current
B)clouds formed by surface heating
C)clouds forming behind a jet airplane
D)clouds forming on the windward slope of a mountain

Question 41

Which of the following can be determined when you have knowledge of air stability?

A)the direction of movement of storms
B)the movement of high pressure areas
C)the vertical motion of air
D)seasonal weather patterns

Question 42

Which of the following pr°Cesses changes a moist layer of stable air into a deck of low strat°Cumulus clouds?

A)mixing
B)heating the top of the layer
C)lifting
D)cooling the surface

Question 43

Which of the following describes the atmosphere when an air parcel is given a small push upward and it falls back to its original position?

A)isothermal
B)unstable
C)neutral
D)stable

Question 44

Which of the following conditions describes when a parcel of saturated air releases the most latent heat?

A)when the air parcel is rising and cold
B)when the air parcel is rising and warm
C)when the air parcel is sinking and warm
D)when the air parcel is sinking and cold

Question 45

In which of the following l°Cations is a rotor cloud most likely observed?

A)in absolutely unstable air
B)in the middle of a cumulonimbus
C)on top of a developing cumulus cloud
D)beneath a lenticular cloud

Question 46

Which of the following cloud types most likely forms in an unstable atmosphere?

A)stratus
B)cirrostratus
C)cumulonimbus
D)nimbostratus

Question 47

Which of the following gives an example of orographic clouds?

A)rotor clouds
B)lee wave clouds
C)cumulus clouds produced by surface heating
D)clouds that form on the upwind slope of a mountain

Question 48

Which of the following describes what tends to happen to a large environmental lapse rate during vertical mixing of air?

A)it decreases
B)it remains the same
C)it increases
D)it increases at first, followed by a decrease

Question 49

Which of the following air motions °Ccur in a sky filled with scattered cumulus humilis clouds?

A)Rising motions occur between the clouds, and sinking motions occur under them.
B)Rising motions occur between the clouds, and sinking motions occur between them.
C)Rising motions occur under the clouds, and sinking motions occur under them.
D)Rising motions occur under the clouds, and sinking motions occur between them.

Question 50

Suppose a conventional jet airliner is at an altitude of 10 km, the outside air pressure is 250 hPa, and the outside temperature is -60C. What would be the air temperature inside the jet if the outside air is brought inside and compressed to a 1000 hPa pressure? (Assume that 1000 hPa pressure is equivalent to 0 m altitude.)

A)6011efbc95_3126_a591_ad5f_1348e684797a_TB1378_00C
B)4011efbc95_3126_a591_ad5f_1348e684797a_TB1378_00C
C)011efbc95_3126_a591_ad5f_1348e684797a_TB1378_00C
D)-6011efbc95_3126_a591_ad5f_1348e684797a_TB1378_00C

Question 51

Which of the following describes the behaviour of sinking air?

A)warms adiabatically
B)cools adiabatically
C)remains adiabatically constant
D)constantly varies adiabatically

Question 52

Which of these lapse rates remains constant?

A)moist adiabatic lapse rate
B)dry adiabatic lapse rate
C)air adiabatic lapse rate
D)environmental lapse rate

Question 53

Which of the following cloud types are commonly found downwind of a mountain?

A)mammatus clouds
B)anvil clouds
C)lenticular clouds
D)contrails

Question 54

Which of the following statements describes the air motions beneath and between fair-weather cumulus (cumulus humilis) clouds?

A)Downdrafts occur beneath them, and updrafts occur between them.
B)Updrafts occur beneath them, and horizontal motions occur between them.
C)Downdrafts occur beneath them, and horizontal motions occur between them.
D)Updrafts occur beneath them, and downdrafts occur between them.

Question 55

Which of the following is found just above cumulus humilis clouds?

A)a conditionally unstable layer
B)a stable layer
C)an unstable layer
D)unusually strong horizontal winds

Question 56

Which of the following surface conditions produces a cumulus cloud with the lowest base?

A)air temperature 32°C and dew point 4°C
B)air temperature 32°C and dew point -7°C
C)air temperature 32°C and dew point 10°C
D)air temperature 32°C and dew point 16°C

Question 57

Which of the following describes a conditionally unstable atmosphere?

A)stable with respect to unsaturated air and unstable with respect to saturated air
B)unstable with respect to unsaturated air and stable with respect to saturated air
C)unstable with respect to unsaturated air and unstable with respect to saturated air
D)stable with respect to unsaturated air and stable with respect to saturated air

Question 58

Suppose you take a trip during the summer from Ontario to Alberta. Which of the following describes the afternoon cumulus clouds you likely observe as you travel west?

A)The clouds have higher cloud bases.
B)The clouds disappear.
C)The clouds form earlier in the day.
D)The clouds are larger.

Question 59

Which of the following pr°Cesses increases the environmental lapse rate?

A)cold advection at higher altitudes and daytime solar heating
B)warm advection at higher altitudes and daytime radiational cooling
C)daytime solar heating and surface radiational cooling
D)cold advection at higher altitudes and surface radiational cooling

Question 60

Which of the following terms refers to the temperature of an air parcel that is moved to a pressure of 1000 hPa at the dry adiabatic rate?

A)dew point temperature
B)potential temperature
C)descending temperature
D)adiabatic temperature

Question 61

Which of the following terms refers to the type of instability that °Ccurs when unsaturated stable air is lifted to a level where it becomes saturated and unstable?

A)forced instability
B)convective instability
C)baroclinic instability
D)conditional instability

Question 62

List and explain the four pr°Cesses that cause rising air motions in the atmosphere.

Question 63

Does radiational cooling at the ground at night act to increase or decrease atmospheric stability? How does daytime heating at the ground during the day affect atmospheric stability?

Question 64

What types of clouds might you see form when a cold mass of air moves over warmer water?

Question 65

Explain why the dry adiabatic lapse rate is different than the saturated adiabatic lapse rate.

Question 66

Which of the following conditions is necessary for a layer of altostratus clouds to change into alt°Cumulus?

A)The cloud layer becomes more stable.
B)The top part of the cloud deck cools while the bottom part warms.
C)The cloud layer mixes.
D)Temperature increases with increasing altitude in the layer.

Question 67

Explain how lifting an air layer can steepen the environmental lapse rate and make the layer more unstable.

Question 68

Which of the following atmospheric conditions °Ccurs when the environmental lapse rate decreases more rapidly with height than the dry adiabatic rate?

A)absolutely unstable
B)absolutely stable
C)convectively unstable
D)conditionally unstable

Question 69

An air parcel that is warmer than its surroundings will rise. What force accounts for this upward motion?

Question 70

Explain why the surface air on the downwind side of a mountain can be drier than the surface air on the upwind side. What is this effect called? Can you think of a l°Cation in Canada where this might °Ccur?

Question 71

Explain why clouds form in rising air. Would it be possible for rising air to remain cloud-free?

Question 72

Cumulonimbus clouds indicate unstable atmospheric conditions. What stops the upward growth and causes the top of a cumulonimbus cloud to flatten out into an anvil?

Question 73

Suppose you observe lenticular clouds that appear to be motionless. Is the air in the vicinity of the cloud motionless? Explain.

Question 74

Explain why a rising parcel of air expands and cools.

Question 75

Referring to the figure below, which of the following accurately describes the air temperature and dew point at A and B. ​

A)The temperature and dew point are both colder at A compared to B
B)The temperature is colder and the dew point is higher at A compared to B
C)The temperature is warmer and the dew point is lower at A compared to B.
D)The temperature is warmer and the dew point is higher at A compared to B.

Question 76

Do clear skies accompany stable, unstable, or neutral stability conditions? Explain your answer.

Question 77

Which of the following conditions are often indicated by soaring birds in flight, such as hawks and eagles?

A)irreversible pseudoadiabatic processes
B)subsidence inversions
C)absolute instability
D)thermals

Question 78

Based on atmospheric stability considerations, do you think it would be best to burn agricultural debris in the early morning or the afternoon?

Question 79

Under what conditions can a cloud form when air is sinking?

Question 80

Explain how the stability of the atmosphere can affect the types of clouds that form.