Deck 6: Stability and Cloud Development

Question 1

The environmental lapse rate decreases because of cold advection at higher altitudes and daytime solar heating.

Answer 1

False

Question 2

Usually when a cumulonimbus cloud begins to dissipate, the bottom half of the cloud dissipates first.

Answer 2

True

Question 3

The up-and-down motions in layered clouds produce globular elements that give the clouds lumpy appearances.

Answer 3

True

Question 4

Warm saturated air produces more liquid water than cold saturated air.

Question 5

The environmental lapse rate is almost always the same as the adiabatic rate.

Question 6

A layer of altostratus can change into one of altocumulus if the top of the original cloud deck cools while the bottom warms.

Question 7

If an air parcel is given a small push upward and it falls back to its original position, the atmosphere is said to be ____.

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

Question 8

The temperature of rising air at a given level inside a cumulus cloud is normally warmer than the air around the cloud.

Question 9

The combination of warming the surface and warming the air aloft creates the greatest atmospheric stability.

Question 10

Subsidence inversions are just as common on Earth's surface as they are aloft.

Question 11

Cumulus clouds are a common phenomenon over cool water surfaces.

Question 12

Environmental lapse rate and dry adiabatic rate are different expressions for the same phenomenon.

Question 13

Convective instability associated with severe thunderstorms and tornadoes can be brought on by lifting a stable air layer whose surface is humid and whose top is dry.

Question 14

It is possible for a layer of air to be convectively unstable and absolutely stable at the same time.

Question 15

Subsidence has no effect on atmospheric stability.

Question 16

The atmosphere is normally most stable in the early morning and most unstable in the afternoon.

Question 17

Sinking air sometimes cools adiabatically.

Question 18

The safest place to build an airport in a mountainous region is along a deep valley.

Question 19

A rising parcel of air expands and cools, whereas a sinking parcel is compressed and warms.

Question 20

Billow clouds form along the top of a cloud layer when changes in wind speed and direction reach a critical value, and an inversion caps the cloud-forming layers.

Question 21

If an air parcel is given a small push upward and it continues to move upward on its own accord, the atmosphere is said to be ____.

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

Question 22

The largest amount of latent heat gets released in a ____ parcel of ____ saturated air.

A)rising; warm
B)rising; cold
C)sinking; warm
D)sinking; cold
E)stagnant; medium-temperature

Question 23

At Earth's surface, a rising saturated air parcel cools at the ____.

A)moist adiabatic rate
B)dry adiabatic rate
C)condensation rate
D)saturation rate
E)development rate

Question 24

The difference between "moist" and "dry" adiabatic rates is a result of the fact that _______.

A)saturated air is always unstable
B)an unsaturated air parcel expands more rapidly than a saturated air parcel
C)moist air weighs less than dry air
D)latent heat is released by a rising parcel of saturated air
E)moist air weighs more than dry air

Question 25

Which environmental lapse rate represents the most UNSTABLE atmosphere in a layer of unsaturated air?

A)1 degree Celsius per 1,000 m
B)3 degrees Celsius per 1,000 m
C)6 degrees Celsius per 1,000 m
D)9 degrees Celsius per 1,000 m
E)11 degrees Celsius per 1,000 m

Question 26

Most thunderstorms do not extend very far into the stratosphere because the air in the stratosphere is ____.

A)unstable
B)stable
C)too cold
D)too thin
E)too dry

Question 27

A knowledge of air stability is important because it determines ____.

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

Question 28

Which of the following sets of conditions would produce a cumulus cloud with the LOWEST base?

A)Air temperature 90 degrees Fahrenheit, dew point temperature 50 degrees Fahrenheit
B)Air temperature 90 degrees Fahrenheit, dew point temperature 40 degrees Fahrenheit
C)Air temperature 90 degrees Fahrenheit, dew point temperature 60 degrees Fahrenheit
D)Air temperature 90 degrees Fahrenheit, dew point temperature 20 degrees Fahrenheit
E)Air temperature 90 degrees Fahrenheit, dew point temperature 10 degrees Fahrenheit

Question 29

Which condition would be described as the most stable ?

A)Environmental lapse rate is 13 degrees Celsius per kilometer
B)Environmental lapse rate is 3 degrees Celsius per kilometer
C)Isothermal conditions
D)An inversion
E)Superadiabatic conditions

Question 30

Which of the following is NOT a mechanism primarily responsible for most clouds observed?

A)Surface heating and free convection
B)Uplift along topography
C)Differences to air pressure caused by a rapidly increasing moist adiabatic rate in a thermal
D)Widespread ascent due to convergence of surface air
E)Uplift along weather fronts

Question 31

In a conditionally unstable atmosphere, the environmental lapse rate will be ____ the moist adiabatic rate and ____ the dry adiabatic rate.

A)greater than; less than
B)greater than; greater than
C)less than; greater than
D)less than; less than
E)the same as; the same as

Question 32

The dry adiabatic rate is ____ greater than the moist adiabatic rate.

A)never
B)sometimes
C)always
D)most of the time
E)half the time

Question 33

The dry adiabatic rate is the rate at which ____.

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

Question 34

Which cloud type below would most likely form in an UNSTABLE atmosphere?

A)Cumulonimbus
B)Stratus
C)Cirrostratus
D)Nimbostratus
E)Cumulus humilis

Question 35

The rate at which the actual air temperature changes with increasing height above the surface is referred to as the ____ rate.

A)dry adiabatic
B)environmental lapse
C)moist adiabatic
D)thermoclinic
E)absolute stability

Question 36

Just above cumulus clouds, you would expect to find ____.

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

Question 37

If rising air cools to its dew-point temperature, the relative humidity becomes _____.

A)20 percent
B)40 percent
C)60 percent
D)80 percent
E)100 percent

Question 38

A rising parcel of air that does not exchange heat with its surroundings is an example of ____.

A)isothermal ascent
B)an adiabatic process
C)forced lifting
D)advection
E)convection

Question 39

An inversion represents an extremely stable atmosphere because air that rises into the inversion will eventually become ____ and ____ dense than/as the surrounding air.

A)warmer; less
B)warmer; more
C)colder; less
D)colder; more
E)warmer; similarly

Question 40

The rate at which the temperature changes inside a rising (or descending)parcel of SATURATED air is called the ____ rate.

A)environmental lapse
B)dry adiabatic
C)moist adiabatic
D)latent heat release
E)specific heat release

Question 41

Absolute instability results when the environmental lapse rate is ____ the ____ adiabatic rate.

A)greater than; moist
B)less than; moist
C)the same as; dry
D)greater than; dry
E)less than; dry

Question 42

When cloud elements become arranged in rows they are called cloud ____.

A)roads
B)trails
C)billows
D)rows
E)streets

Question 43

An air parcel in an unstable atmosphere has ____ force acting on it.

A)no
B)a sideways-directed
C)a downward-directed
D)a diagonally directed
E)an upward-directed

Question 44

What transfers heat upward into the atmosphere?

A)Cloud streets
B)Billows
C)Thermals
D)Subsidence inversions
E)Pockets of saturated air

Question 45

Suppose the surface air temperature is 66 degrees Fahrenheit. If the base of a cumulus congestus cloud directly above you is 2,000 feet, what would be the approximate temperature at an altitude of 5,000 feet above you inside the cloud? (Hint: the dry adiabatic rate is 5.5 degrees Fahrenheit per 1,000 feet; the moist adiabatic rate is 3.0 degrees Fahrenheit per 1,000 feet.)

A)55 degrees Fahrenheit
B)49 degrees Fahrenheit
C)46 degrees Fahrenheit
D)41 degrees Fahrenheit
E)32 degrees Fahrenheit

Question 46

Neutral stability is a condition in which ____.

A)the environmental lapse rate is equal to the dry adiabatic rate and the moist adiabatic rate.
B)the environmental lapse rate is greater than the moist adiabatic rate but less than the dry adiabatic rate
C)the environmental lapse rate is greater than the dry adiabatic rate but less than the moist adiabatic rate
D)the environmental lapse rate is equal to the moist adiabatic rate
E)the environmental lapse rate is equal to the dry adiabatic rate.

Question 47

Air that resists vertical displacements is considered to be ____.

A)stable
B)unstable
C)neutral
D)supersaturated
E)entrained

Question 48

Which condition below is necessary for a layer of altostratus clouds to change into altocumulus?

A)The top part of the cloud deck cools while the bottom part warms.
B)Temperature increases with increasing altitude in the layer.
C)The cloud layer becomes more stable.
D)The cloud layer becomes clear.
E)The nuclei types within the cloud have to change.

Question 49

Forced lifting along a topographic barrier is called ____.

A)orographic rising
B)orographic uplift
C)topographical uplift
D)topographical uprise
E)orographic uprise

Question 50

The elevation where clouds form is called ____ level.

A)condensation
B)saturation
C)precipitation
D)cloud formation
E)adiabatic

Question 51

If you were to take a trip during the summer from Ohio to Nevada, you would most likely observe that afternoon cumulus clouds as you travel west.

A)have higher cloud bases
B)are larger
C)form earlier in the day
D)Disappear
E)form later in the day

Question 52

Conditional instability occurs whenever the environmental lapse rate is ____ the moist adiabatic rate and the dry adiabatic rate.

A)higher than
B)less than
C)between
D)the same as
E)double

Question 53

Which process will change a moist layer of stable air into a deck of low stratocumulus clouds?

A)Mixing
B)Lifting
C)Cooling the surface
D)Heat the top of the layer
E)Subsidence

Question 54

Lenticular clouds that form in the wave directly over a mountain are called ____.

A)cumulus clouds produced by surface heating
B)rotor clouds
C)lee-wave clouds
D)mountain wave clouds
E)pileus clouds

Question 55

If the environmental lapse rate is less than the moist adiabatic rate, the atmosphere is ____.

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

Question 56

If the environmental lapse rate is 5 degrees Celsius per 1000 m and the temperature at Earth's surface is 25 degrees Celsius, then the air temperature at 2000 m above the ground is ____.

A)25 degrees Celsius
B)30 degrees Celsius
C)20 degrees Celsius
D)15 degrees Celsius
E)10 degrees Celsius

Question 57

In a sky filled with scattered cumulus humilis clouds, rising motions are found ____ the clouds and sinking motions are found ____ the clouds.

A)between; above
B)under; between
C)under; under
D)between; between
E)above; under

Question 58

Conditional instability depends on the condition of ____.

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

Question 59

When the environmental lapse rate is between the moist adiabatic rate and the dry adiabatic rate is a situation known as ____.

A)an absolutely unstable atmosphere
B)an absolutely stable atmosphere
C)a subsidence inversion
D)neutral stability
E)a conditionally unstable atmosphere

Question 60

An example of orographic clouds would be clouds ____.

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

Question 61

The atmosphere is normally most stable in the ________________ and most unstable in the ________________.

Question 62

Inversions that form as air slowly sinks over a large area are called ____________________ inversions.

Question 63

Lenticular clouds form on the ____________________ side of mountains.

Question 64

Rain shadows form on the ____________________ side of mountains.

Question 65

The stability of the atmosphere above the condensation level plays a major role in determining the vertical growth of a cumulus cloud. When a deep conditionally unstable layer exists above the cloud base, ____ are likely to grow.

A)cumulus humilis
B)billow clouds
C)cumulus congestus
D)cumulonimbus
E)lenticular clouds

Question 66

Which of the following is NOT a typical reason surface air warms?

A)Daytime solar heating of the surface
B)An influx of warm air brought in by the wind
C)Air moving over a warm surface
D)Warm advection
E)Clouds emitting infrared radiation

Question 67

A(n)____________________ process is a process in which an air parcel expands and cools, or compresses and warms, with no interchange of heat with its surroundings.

Question 68

Inversions that form as air slowly sinks over a large area are called ____ inversions.

A)surface
B)surficial
C)ground-cover
D)ground
E)subsidence

Question 69

Altocumulus castellanus appearing in the sky indicates that the mid-level of the troposphere is becoming ____.

A)more unstable
B)less unstable
C)conditionally stable
D)more stable
E)more conditionally stable

Question 70

Dry adiabatic cooling and warming rates are approximately ____ of change in elevation.

A)4 degrees Celsius for every 1,000 m
B)6 degrees Celsius for every 1,000 m
C)8 degrees Celsius for every 1,000 m
D)10 degrees Celsius for every 1,000 m
E)12 degrees Celsius for every 1,000 m

Question 71

At Earth's surface, a parcel of air has ____ the air surrounding it.

A)the same temperature, but lower pressure than
B)a lower temperature, but higher pressure than
C)a higher temperature, but lower pressure
D)a higher temperature, but the same pressure as
E)the same temperature and pressure as

Question 72

A conditionally unstable atmosphere is ____________________ with respect to unsaturated air and ____________________ with respect to saturated air.

Question 73

An afternoon sky full of cumulus humilis clouds with little vertical growth indicates ____ weather.

A)stormy
B)fair
C)cold
D)snowy
E)rainy

Question 74

When rising air cools to its dew-point temperature, its relative humidity typically is ____ percent.

A)60
B)70
C)80
D)90
E)100

Question 75

In an air parcel the average speed of the molecules is directly related to the air ____________________, and the molecules colliding against the parcel walls determine the air ____________________ inside.

Question 76

Unlike the dry adiabatic rate, the moist adiabatic rate is not constant but varies greatly with ____________________ and, hence, with moisture content.

Question 77

If the atmosphere is conditionally unstable, the condition necessary to bring on instability is called ____________________.

Question 78

Layered clouds tend to form in a ______________ atmosphere, whereas cumuliform clouds tend to form in a ______________________ atmosphere.

Question 79

When air is stable and close to saturation, stratocumulus clouds can be produced by a process called ____________________.

Question 80

Altocumulus clouds that show vertical development and produce tower-like extensions are called ____.

A)cumulus
B)cumulonimbus
C)cumulus humilis
D)altocumulus castellanus
E)cirrocumulus castellanus