Assignment 10 



Air Masses and Fronts; Meteorological Elements 



Text: Pages 322 - 355 



Learning Objective: Recognize the 

 relationship between fronts and air 

 masses, and identify types of fronts 

 and weather conditions associated 

 with each type. 



10-1. Which of the following air mass properties 

 is conservative with respect to dry 

 adiabatic temperature changes but is 

 nonconservative with respect to moist 

 adiabatic temperature changes? 



1. Temperature 



2. Potential temperature 



3. Wet-bulb temperature 



4. Potential wet-bulb temperature 



10-2. Which two properties are conservative 



relative to both dry and moist adiabatic 

 temperature changes? 



1. equivalent potential temperature and 

 relative humidity 



2. wet-bulb temperature and relative 

 humidity 



3. wet-bulb temperature and potential 

 wet-bulb temperature 



4. equivalent potential temperature and 

 potential wet-bulb temperature 



10-3. 



Which of the following phrases best 

 defines the term "front"? 



1. The boundary between air masses 



2. The centers of action of air masses 



3. The regions of transition between 

 air masses 



4. The zone of convergence of air masses 



10-5. A line of discontinuity at the earth's 



surface along which warm air is displaced 

 by cold air is known as 



1. a cold front 



2. a warm front 



3. a stationary front 



4. an occluded front 



10-6. The passage of a cold front is accom- 

 panied by 



1. rising pressure 



2. increasing humidity 



3. increasing temperature 



4. constant wind direction 



In items 10-7 through 10-9, select from column B 

 the type of front associated with each movement 

 of warm air described in column A. 



A. Warm Air Movements B. Fronts 



10-7. A descending motion of 

 warm air along the 

 frontal surface at high 

 levels, with warm air 

 near the surface being 

 pushed upward vigorously 



10-8. An advancing warm air 



mass replacing a retreat- 

 ing colder air mass 



10-9. A general upglide of warm 

 air along the entire 

 frontal surface, with pro- 

 nounced lifting along its 

 lower portion 



Slow-moving 

 cold front 



Warm type 

 occlusion 



Fast-moving 

 cold front 



Warm front 



10-4. 



The most important region of transition 

 between two air masses over the United 

 States is the 



1. ITCZ 



2. doldrums 



3. polar front 



4. Antarctic front 



10-10. The passage of which type of front is 



usually accompanied by a relatively nar- 

 row but often violent band of weather? 



1. Warm front 



2. Stationary front 



3. Slow^moving cold front 



4. Fast-moving cold front 



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