Assignment 9 



Circulation of the Atmosphere; Air Masses and Frosts 



Text: Pages 289 - 322 



Learning Objective: Identify types 

 and causes of circulations of the 

 earth's atmosphere. 



9-1. The sun's radiation is the primary factor 

 in the production of horizontal and verti- 

 cal motion of air in the earth's atmos- 

 phere, but the horizontal motion is 

 directly caused by the 



1. expansion of air as it is warmed 



2. contraction of air as it is cooled 



3. pressure differential over the earth's 

 surface 



4. temperature differential over the 

 earth's surface 



9-2. Which type of circulation signifies that 



air motion was modified by a minor, local, 

 meteorological condition? 



1. Secondary 



2. Primary 



3. General 



4. Tertiary 



Learning Objective: Recognize charac- 

 teristics and effects of temperature, 

 pressure, earth rotation, and wind on 

 the general circulation of the 

 atmosphere. 



9-3. Where and when do the steepest temperature 

 gradients occur? 



1. In the middle and high latitudes of 

 each hemisphere in summer 



2. In the middle and high latitudes of 

 each hemisphere in winter 



3. In the tropical and subtropical lati- 

 tudes of each hemisphere in winter 



4. In the tropical and subtropical lati- 

 tudes of each hemisphere in summer 



9-4. Refer to figure 13-1 in your textbook. 



Approximately how much do the January and 

 July mean temperatures vary in the area of 

 40° N, 80° W? 



1. 12° 



2. 24° 



3. 48° 



4. 72° 



9-5. The polar regions are dominated by areas of 



1. high pressure throughout the entire 

 year 



2. low pressure throughout the entire 

 year 



3. high pressure in the summer, and low 

 pressure in the winter 



4. low pressure in the summer, and high 

 pressure in the winter 



9-6. What might be concluded about the earth 

 if, without variation, the wind circula- 

 tion was always due poleward aloft and 

 directly opposite at the surface? 



1. The earth is a uniform, rotating sphere 



2. The earth is a uniform, nonrotating 

 sphere 



3. The earth is a nonuniform, rotating 

 sphere 



4. The earth is a nonuniform, nonrotating 

 sphere 



9-7. How does the Coriolis force affect 

 windf low? 



1. It causes wind deflection to the right 

 in both the Northern and Southern 

 Hemispheres 



2. It causes wind deflection to the left 

 in both the Northern and Southern 

 Hemispheres 



3. It causes wind deflection to the left 

 in the Northern Hemisphere and to the 

 right in the Southern Hemisphere 



4. It causes wind deflection to the right 

 in the Northern Hemisphere and to the 

 left in the Southern Hemisphere 



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