10-53. Accretion is the process by which water 

 droplets do which of the following? 



1. Evaporate and then sublimate dir- 

 ectly into ice crystals 



2. Sublimate into ice crystals because 

 of air turbulence 



3. Grow in size by continuing 

 condensation 



4. Accumulate more layers by colliding 

 with and holding smaller droplets 



In items 10-59 through 10-61, select from col- 

 umn B the class of cloud that is confined in 

 each etage listed in column A. 



A. Etages 



B. Classes of Clouds 



10-59. 



High 



1. 



Altocumulus 



10-60. 



Middle 



2. 



Cirrocumulus 



10-61. 



Low 



3. 



Cumulus 



Learning Objective: Recognize how 

 clouds are formed, their classifi- 

 cation according to composition, 

 appearance, and size, and identify 

 precipitation associated with 

 certain types of clouds. 



10-54. Clouds form most commonly as the direct 

 result of 



1. condensation 



2. evaporation 



3. sublimation 



4. crystallization 



10-55. Refer to the preceding item. In order 

 for this to occur, three conditions 

 must be met. These conditions include 

 the presence of all the following EXCEPT 



1. wind 



2. moisture 



3. a cooling process 



4. hygroscopic nuclei 



In items 10-56 through 10-58, select from 

 column B the condensation inducing cooling pro- 

 cess which applies to each condition in column A. 



A. Conditions 



10-56. Two masses of air with 

 different densities 

 meet, and the mass 

 having less density 

 moves up and over the 

 mass having the 

 greater density 



10-57. A mass of air in con- 

 tact with the surface is 

 cooled to its dewpoint 

 by contact cooling 



10-58. A limited mass of air is 

 heated on the surface and 

 ascends through the atmos- 

 phere until its temperature 

 is equal to, or less than, 

 that of the surrounding air 



Stratocumulus 



B. 



Cooling 

 Processes 



1. 



Convective 



2. 



Radiational 



3. 



Mechanical 



4. 



Orographic 



10-62. What cloud genera abbreviation is 



associated with clouds described as 

 sheep-back-like clouds? 



1. AC 



2. CB 



3. CC 



4. SC 



10-63. Altocumulus, stratocumulus, and occa- 

 sionally cirrocumulus clouds which are 

 spread out in an extensive horizontal 

 sheet or layer are identified as what 

 species? 



1. Castellanus 



2. Fractus 



3. Uncinus 



4. Stratiformis 



10-64. For classification purposes, clouds are 

 divided into etages, genera, species, 

 and varieties. Variety refers to a 

 cloud's 



1. height 



2. description 



3. size 



4. transparency 



10-65. Clouds described as detached, delicate, 

 with a fibrous appearance are identified 

 as 



1. Cirrostratus 



2. Fractostratus 



3. Cirrus 



4. Stratocumulus 



10-66. The ice crystal composition of a cirrus 

 cloud determines which characteristic 

 of this high etage cloud? 



1. Shape 



2. Height 



3. Transparency 



4. Size 



62 



