Earth System Science 5: THE ATMOSPHERE / Homework 5 (due 5/22/2008)
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MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

6) Of the following steps in the Bergeron process, which should be second?

1) The terminal velocity of an object depends primarily upon:

A) the falling of ice crystals through the cloud B) formation of rain drops

A) its size.

C) deposition of water vapor on ice

B) the temperature.

D) net evaporation from supercooled water droplets C) its shape.
D) its composition.

7) Raindrops fall because:

2) The collision-coalescence process:

A) they are small compared to atmospheric molecules. A) explains the formation of snow better than it explains the formation of rain.

B) they become large enough that gravity can pull them out of the sky.

B) is most frequent in cold clouds.
C) is dependent upon the different downward velocities of different-sized droplets. C) they roll down isentropic surfaces and can't be stopped.
D) they are large compared to atmospheric molecules. D) is most common at high latitudes.
3) The process by which supercooled water droplets freeze onto falling ice crystals is called: 8) Aggregation:
A) is the first step of the Bergeron process.
B) is another term for riming.

A) riming.

C) is facilitated by a thin coating of water on ice crystals.

B) aggregation.
C) Bergeron bonding.

D) works best when the cloud temperature is
-10 degrees Celsius or colder.

D) cold-cloud condensation.
4) Cloud droplet growth by condensation is very rapid for:

9) The largest form of precipitation is:
A) drizzle.

A) supercooled water droplets.

B) snow.

B) ice crystals.

C) hail.

C) large cloud droplets.

D) graupel.

D) small cloud droplets.

E) rain.

E) none of the above

10) Hail:

5) Given that the diameter of the average raindrop is 100 times that of the average cloud droplet, the volume of the average raindrop is about this many times greater than that of the average cloud droplet:
A) 100 times.

B) requires very strong downdrafts.
C) most frequently occurs in sizes greater than two centimeters in diameter.

B) 1000 times.

C) 10000 times.

A) usually forms in cumuliform clouds.

D) 1000000 times.

D) can provide the nucleus for graupel formation. 1

11) Collision-coalescence is the predominant cause of precipitation in this region:
A) the Tropics.
B) mid-latitudes.
C) subpolar latitudes.
D) above the Arctic Circle.
12) The shape of a raindrop:
A) is not affected by drag.
B) is initially that of a tear.
C) eventually resembles that of a disk.
D) remains constant throughout the journey from cloud to ground.
13) Snow results from all of the following processes, except:
A) coalescence.

B) riming.

C) aggregation.

D) deposition.

14) Cool clouds:
A) have regions with above-freezing temperatures. B) contain substantial numbers of ice crystals at all elevations within the clouds.
C) contain no water droplets above 0 degrees
Celsius.
D) typically form precipitation through the collision-coalescence process.

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Answer Key
Testname: HOMEWORK.5.2008.TST
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
11)
12)
13)
14)

A
C
A
D
D
C
B
C
C
A
A
C
A
A

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