Question 1

Rainshowers:

Accepted Answer

A) typically come from cumuliform clouds. 
B) are, by definition, periods of rain that last for at least one hour. 
C) have only one size of raindrop. 
D) usually have their origin in orographic lifting.

Question 2

What happens to a raindrop if it gets too large?

Accepted Answer

A) evaporates 
B) stays suspended in the cloud 
C) breaks up into smaller drops 
D) turns into a hailstone

Question 3

Cool clouds:

Accepted Answer

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

Question 4

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:

Accepted Answer

A) 100 times. 
B) 1000 times. 
C) 10000 times. 
D) 1000000 times.

Question 5

Ice crystal growth rates are enhanced by which of the following?

Accepted Answer

A) deposition of water vapor to ice alone 
B) riming 
C) aggregation 
D) all of the above

Question 6

Raindrops fall because:

Accepted Answer

A) they are large compared to atmospheric molecules. 
B) they are small compared to atmospheric molecules. 
C) they become large enough that gravity can pull them out of the sky. 
D) they roll down isentropic surfaces and can't be stopped.

Question 7

With reference to the Great Lakes,which of the following mechanisms are favorable for precipitation in that area?

Accepted Answer

A) initial mechanism for uplift 
B) unstable air 
C) sufficient moisture 
D) all of the above

Question 8

The objective of cloud seeding is

Accepted Answer

A) to cause more droplets in a cloud to become supercooled 
B) to convert some of the supercooled droplets in a cool cloud to ice and cause precipitation by the Bergeron process 
C) to convert some of the supercooled droplets in a cool cloud to ice and cause precipitation by the collision/coalescence process 
D) to enhance the evaporation of supercooled cloud droplets

Question 9

Which of the following does not contribute to flood conditions?

Accepted Answer

A) excessive precipitation 
B) saturated soil 
C) water levels in rivers/streams 
D) fog

Question 10

In the United States,hail is most common in which of the following regions?

Accepted Answer

A) West Coast 
B) East Coast 
C) Great Plains 
D) Gulf Coast

Question 11

The growth of ice crystals in the Bergeron-Findeisen process occurs because:

Accepted Answer

A) the relative humidity is higher in a cold cloud than in a warm cloud. 
B) of the difference between saturation vapor pressure between ice and water. 
C) liquid water is attracted to ice because of an electrical charge differential. 
D) updrafts are extremely strong during the Bergeron-Findeisen process.

Question 12

Describe the important steps and processes of the formation of precipitation in the Bergeron process,starting with a mixture of small ice crystals and supercooled water droplets and ending with the dropping of precipitation from a cloud.

Accepted Answer

The answer of Describe the important steps and processes of...

Question 13

Raindrops fall to the ground when:

Accepted Answer

A) they are at least five times the size of a cloud droplet. 
B) they reach a large enough terminal velocity for both their size and the distance between them and the ground. 
C) they are able to catch a fast-moving downdraft. 
D) the coalescence rate exceeds that of the collision rate.

Question 14

Which of the following is a widely held misconception about snowfall and temperature?

Accepted Answer

A) It's too cold to snow. 
B) It's too cold to snow a lot. 
C) Snow only falls at the freezing point. 
D) none of the above

Question 15

Dry growth of a hailstone occurs in an environment

Accepted Answer

A) where repeated trips are made through a cloud. 
B) where the temperature is well below freezing. 
C) with weak upper-level winds. 
D) where the temperature is near freezing.

Question 16

Cloud seeding:

Accepted Answer

A) has been of substantial benefit to farmers on the Great Plains. 
B) uses dry ice to increase the temperature of very cold clouds. 
C) uses silver iodide to promote homogeneous nucleation. 
D) has been able to increase rainfall in the Sierra Nevada under certain conditions.

Question 17

The structure of an ice crystal is mostly determined by the ________ and ________ profiles in the atmosphere.

Accepted Answer

The answer of The structure of an ice crystal is...

Question 18

Sleet:

Accepted Answer

A) requires the presence of a warmer above-freezing inversion layer. 
B) freezes immediately upon touching the surface. 
C) is usually associated with a cold front. 
D) is more dangerous than freezing rain.

Question 19

In comparison to liquid water,the density of the ice in hail is:

Accepted Answer

A) 50% of water. 
B) 70% of water. 
C) 90% of water. 
D) no difference

Question 20

Describe in detail the formation of precipitation in both the collision-coalescence process and the Bergeron process.

Accepted Answer

The answer of Describe in detail the formation of precipitation...

Exam 7: Precipitation Processes