Deck 5: Clouds and Stability

Question 1

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

A)warmer,less
B)warmer,more
C)colder,less
D)colder,more

Answer 1

D

Question 2

Which of the following would increase the environmental lapse rate?

A)cold advection at higher altitudes
B)daytime solar heating
C)surface radiational cooling
D)all of the above
E)both (a)and (b)

Answer 2

E

Question 3

Which of the following set of surface conditions would produce a convective cumulus cloud with the highest base?

A)air temperature 40 ^oC,dew point 30 ^oC
B)air temperature 25 ^oC,dew point 10 ^oC
C)air temperature 35 ^oC,dew point 10 ^oC
D)air temperature 45 ^oC,dew point 25 ^oC
E)air temperature 25 ^oC,dew point 5 ^oC

Answer 3

C

Question 4

The most latent heat would be released in a __________ parcel of __________ saturated air.

A)rising,warm
B)rising,cold
C)sinking,warm
D)sinking,cold

Question 5

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.

Question 6

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 7

The difference between the "moist" and "dry" adiabatic rates is due to:

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

Question 8

At the earth's surface,a rising saturated air parcel would cool most rapidly when its temperature is:

A)10 ^oF.
B)32 ^oF.
C)50 ^oF.
D)68 ^oF.
E)80 ^oF.

Question 9

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 10

A conditionally unstable atmosphere is __________ with respect to unsaturated air
And __________ with respect to saturated air.

A)unstable,stable
B)unstable,unstable
C)stable,unstable
D)stable,stable

Question 11

Subsidence inversions are best developed with __________ pressure areas because of the __________ air motions associated with them.

A)high,rising
B)high,sinking
C)low,rising
D)low,sinking

Question 12

__________ are found beneath fair-weather cumulus (cumulus humilis)clouds,whereas __________ are found between the clouds.

A)downdrafts;updrafts
B)updrafts;downdrafts
C)downdrafts;only horizontal motions
D)updrafts;only horizontal motions

Question 13

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

A)3^o C per 1,000 m
B)6^o C per 1,000 m
C)9^o C per 1,000 m
D)11^o C per 1,000 m

Question 14

Convective instability associated with severe thunderstorms and tornadoes can be brought on by:

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

Question 15

Vertical mixing of air tends to __________ a large environmental lapse rate.

A)decrease
B)increase

Question 16

What two sets of conditions,working together,will make the atmosphere the most unstable?

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

Question 17

Sinking air _________ cools adiabatically.

A)sometimes
B)never
C)always

Question 18

Which of the following statements is/are correct?

A)convection can occur over the ocean
B)air motions are usually downward around a cumulus cloud
C)the temperature of the rising air at a given level inside a cumulus cloud is normally warmer that
The air around the cloud
D)all of the above

Question 19

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

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

Question 20

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

A)air temperature 90^o F,dew point temperature 50^o F
B)air temperature 90^o F,dew point temperature 40^o F
C)air temperature 90^o F,dew point temperature 60^o F
D)air temperature 90^o F,dew point temperature 20^o F

Question 21

Figure 5.15d shows cloud formation by lifting along weather fronts.

Question 22

Subsidence increases stability.

Question 23

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

Question 24

List and explain the four processes that cause rising air motions in the atmosphere.

Question 25

Conditional instability depends on the condition of saturation.

Question 26

Air which resists vertical displacements is considered to be stable.

Question 27

If the environmental lapse rate is 5^o C per 1,000 m and the temperature at the earth's surface is 25^o C,then the air temperature at 2,000 m above the ground is 20^o C.

Question 28

If a parcel of unsaturated air with a temperature of 30^o C rises from the surface to an altitude of 1,000 m,the unsaturated parcel temperature at this altitude would be about 10^o C warmer than at the surface.

Question 29

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

Question 30

Figure 5.15b shows cloud formation by convergence.

Question 31

Would you expect to find a subsidence inversion to be associated with high or low pressure? What effects might a subsidence inversion have on weather conditions at the ground?

Question 32

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

Question 33

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 location in the United States where this might actually occur?

Question 34

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

Question 35

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

Question 36

Figure 5.15a shows cloud formation by convection.

Question 37

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

Question 38

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 39

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

Question 40

Figure 5.15c shows cloud formation by convection.

Question 41

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 42

Describe the changes in atmospheric stability throughout a 24 hour period beginning at sunrise on a cloudless summer day over land.

Question 43

Would you expect clear skies to accompany stable,unstable,or neutral stability conditions? Explain your answer.