Download Spring 2007 - Exam 1

ATMO 336 – Section 002
Exam 1 – Spring 2007
Name__________________________
Write all answers on the answer sheets. Mark your answers clearly. If we cannot
determine your answer, it will be marked wrong. You will turn in both the exam
sheets and the answer sheets. Write your name on both.
Multiple Choice (2 points each)
1. This gas is the most important greenhouse gas on Earth in that it contributes most to the
greenhouse effect.
(a) Water Vapor
(c) Nitrogen
(b) Carbon Dioxide
(d) Oxygen
2. This gas is a toxic pollutant to humans in the lower troposphere. In the stratosphere this
same gas protects us by absorbing ultraviolet radiation from the Sun.
(a) Carbon Dioxide
(c) Ozone
(b) Carbon Monoxide
(d) Sulfur Dioxide
3. The troposphere, tropopause, and stratosphere are layers of the atmosphere defined by the
vertical structure of _______ .
(a) Temperature
(c) Number density
(b) Pressure
(d) Ozone concentration
4. Which of the following generally increases in value as you move upward from the ground to
the top of the troposphere?
(a) air pressure
(c) air density
(b) air temperature
(d) none of the choices given
5. Suppose the air pressure at the ground is measured to be 1013 mb. Which segment of the air
column will be the tallest?
(a) The column of air extending from 1013 mb to 750 mb
(b) The column of air extending from 750 mb to 500 mb
(c) The column of air extending from 500 mb to 250 mb
(d) The column of air extending from 250 mb to 0 mb
6. A skydiver, whose eardrum is in the normal position, jumps out of an airplane. As the
skydiver falls, the shape of his eardrum changes. Which statement best describes how and
why the shape of his eardrum changes?
(a) Eardrum bulges inward as the air pressure in the inner ear cavity decreases
(b) Eardrum bulges inward as the air pressure outside the ear increases
(c) Eardrum bulges outward as the air pressure in the inner ear cavity increases
(d) Eardrum bulges outward as the air pressure outside the ear decreases
7. Which typically takes more time?
(a) A commercial flight from San Francisco to New York
(b) A commercial flight from New York to San Francisco
(c) On average, both flights should take about the same amount of time
(Figure is available under the OLD EXAMS link on course homepage)
Use the 500 mb map above to answer questions 8-13 (Select A-D for questions 8-11)
8. Which marked point is located in a ridge?
9. At which marked point do you expect the temperature to be the most below average?
10. At which marked point would you forecast the lowest (or slowest) 500 mb wind speed?
11. At which marked point would you forecast the best chance of precipitation?
12. The map shown above corresponds to what local time in Tucson?
(a) 5 AM, Saturday, February 17
(c) 5 AM, Sunday, February 18
(b) 5 PM, Saturday, February 17
(d) 5 PM, Sunday, February 18
13. The climatological average value for the mid-February in Tucson is 5690 in the units plotted
on the map above. Based on this information and the map above, what forecast would you
make for Tucson?
(a) Sunny, with much above average temperature
(b) Sunny, with about average temperature
(c) Good chance for rain with about average temperature
(d) Good chance for rain with much below average temperature
14. Throughout the Northern Hemisphere, a typical number of longwaves in the 500 mb pattern
is _________.
(a) 5000
(b) 500
(c) 50
(d) 5
15. A local weather forecaster calls for an upper level ridge to “build” over the western United
States over the next several days. What is most likely to occur in Tucson?
(a) Rain followed by colder conditions (lower temperatures)
(b) Rain followed by warmer conditions (higher temperatures)
(c) Sunny and becoming colder
(d) Sunny and becoming warmer
16. In Tucson, the sea level pressure that is plotted on surface weather maps is __________ than
the air pressure measured with a barometer.
(a) always lower
(b) always higher
(c) sometimes higher and sometimes lower
17. Rising vertical air motion _______________
(a) will more likely be found in the vicinity of a surface high pressure area
(b) will more likely be found in the vicinity of a surface low pressure area
(c) is not at all affected by surface air pressure
18. The air flow around a circular area of low pressure as sea level is generally __________ ; the
air flow around a 500 mb closed low is generally _________.
(a) clockwise ; clockwise
(c) counterclockwise ; clockwise
(b) clockwise ; counterclockwise
(d) counterclockwise ; counterclockwise
19. A large body of cold, dry air (say 1,000 square km) that forms over northern Canada and then
moves southward over the United States is called _________ .
(a) a cyclone
(c) an air mass
(b) an anticyclone
(d) the polar front
20. A surface low pressure area will strengthen (or deepen) with time when upper level
________ is stronger than lower level ________.
(a) divergence ; convergence
(b) convergence ; divergence
21. Numerical weather forecast models are often run forward two weeks into the future, and thus
produce forecast weather conditions 14 days into the future. However, research has shown
that beyond about 10 days into the future, the models have little skill in predicting the
weather. This means that one can guess the weather conditions 10 days into the future
almost as accurately as predicted by the forecast models.
(a) True
(b) False
22. Which process releases the most energy to the surrounding environment?
(a) Condensation of one gram of water
(c) Melting of two grams of water
(b) Evaporation of one gram of water
(d) Freezing of two grams of water
23. For liquid water to evaporate, energy must be ________ to the liquid water. Thus,
evaporation causes __________ of the surrounding environment.
(a) removed ; cooling
(c) added ; cooling
(b) removed ; warming
(d) added ; warming
24. Near the surface of the Earth, which of the following is true most of the time?
(a) the rate of condensation is faster than the rate of evaporation
(b) the rate of evaporation is faster than the rate of condensation
(c) the rate of evaporation equals the rate of condensation
25. Water boils when the saturation vapor pressure is equal to the surrounding air pressure.
Therefore, the temperature of boiling water on Mt. Everest will be _________ than the
temperature of boiling water at sea level.
(a) higher
(b) lower
26. When you can “see your breath” on a cold day, you are seeing __________ .
(a) An air parcel with a high concentration of water vapor
(b) An air parcel of warm air surrounded by colder air
(c) An air parcel that contains tiny droplets of liquid water
Temperature
(ºF)
5
10
15
20
25
30
35
40
45
50
Saturation Mixing Ratio
(g/kg)
1.21
1.52
1.89
2.34
2.88
3.54
4.33
5.28
6.40
7.74
Temperature
(ºF)
55
60
65
70
75
80
85
90
95
100
Saturation Mixing Ratio
(g/kg)
9.32
11.19
13.38
15.95
18.94
22.43
26.48
31.16
36.56
42.78
Use the table of saturation mixing ratios to answer questions 27-29
27. What is the relative humidity of air at a temperature of 90° F and a dew point temperature of
45° F?
(a) 62.5%
(b) 50.0%
(c) 20.5%
(d) 15.0%
28. If the air temperature is 60° F and the relative humidity is 40%, approximately what is the
dew point temperature?
(a) 42° F
(b) 36° F
(c) 30° F
(d) 24° F
29. It is winter in Chicago. The outside air temperature is 10 F and the relative humidity is
90%. If this outside air is heated in a furnace to 65 F, what is the relative humidity of the air
that comes out of the furnace?
(a) 10%
(b) 30%
(c) 50 %
(d) 90%
30. The strong summertime thunderstorms that occasionally form in Arizona are correctly called
monsoons.
(a) True
(b) False
31. A temperature inversion just above the ground surface is most likely to occur ___________.
The reason for this can best be explained by which mechanism of energy transfer?
(a) just before sunset ; radiation
(c) just before sunrise ; radiation
(b) just before sunset ; convection
(d) just before sunrise ; convection
For questions 32-34 consider the following cities all located at sea level. (NOTE: you
should not need to use a table or calculate anything to answer the questions)
City
A
B
C
D
Temperature
30 C
20 C
15 C
10 C
Dew Point Temperature
12 C
18 C
15 C
5 C
32. Which city has the highest water vapor mixing ratio?
(a) A
(b) B
(c) C
(d) D
33. Which city has the highest relative humidity?
(a) A
(b) B
(c) C
(d) D
34. Which city has the highest water vapor saturation mixing ratio?
(a) A
(b) B
(c) C
(d) D
35. Modern home builders use double-paned glass windows because they are better insulators
than older, single-paned glass windows. The reason double-paned windows are better
insulators is that _____________ .
(a) double-paned glass is thicker and hence provides better insulation
(b) an insulating layer of air is placed between the panes of glass
(c) an insulating layer of water is placed between the panes of glass
36. To avoid hyperthermia, the human body responds by _______________ .
(a) shivering and sweating
(c) sweating and vasodilation
(b) shivering and vasoconstriction (d) sweating and vasoconstriction
Short Answer Questions (Select 4 of the 7 Questions) -- 8 Points Each
Write your answers on the attached answer sheets. If you need more space, please use the back
of the multiple choice answer sheet. Your answers should be short and to the point. Make sure
you answer all parts of each question. Points will be deducted for incorrect or unnecessary
statements in your answer, even if the correct answer is found somewhere. Questions
continue on the back of this page.
1. Mountain climbers often use the expression “thin air” to describe atmospheric conditions at
high elevation. For example Jon Krakauer’s book Into Thin Air is about a deadly climbing
expedition to Mount Everest. Explain what it means to say the air gets “thinner” as you
climb upward. In your answer, explain why the air gets “thinner” with increasing
altitude. Briefly explain why it is difficult to breathe in thin air.
2. A 500 mb map is basically a contour map. What is plotted on the map, i.e., what do the
numbers on the map represent? How are the numbers related to the average air
temperature between the ground and 500 mb, i.e., higher numbers mean what? Briefly
explain the reason for this relationship.
3. Considering the continental United States, starting with the fact that the average air
temperature in the lower troposphere decreases as you go from south to north, explain why
the winds at 500 mb generally blow from west toward east. You are expected to
identify the important forces that act on the air.
4. Suppose you are about to begin a rafting trip through the Grand Canyon. A guide unrolls
your inflatable raft on the grass next to the river and pumps air into the raft until it becomes
nice and firm. The raft is then placed onto the cold water of the Colorado River and is
anchored to a tree by a rope. A short time later you notice that the raft has lost its firmness
and has become “baggy”. A whiner in your group cries “Oh no! There is a hole in our raft.
I’m not going!” But you say “Don’t worry the raft lost its firmness because it was put in the
cold water.” Explain why the raft would lose its firmness by explaining what happens to
the temperature, pressure, and number density of the air in the raft after being placed
in the cold water. How can this “problem” be solved?
5. Consider a drinking glass full of ice water (liquid water and lots of ice cubes) that is at a
temperature of 32 F (0 C). To avoid evaporation of the ice water, a lid is placed on top of
the glass. The surrounding air is still (no wind), the air temperature is 60 F, and the dew
point temperature is 45 F. Describe two processes that will act to add energy (or heat) to
the ice water through the sides of the glass (not through the top or bottom). Even
though heat is being added, you notice that the temperature of the ice water inside the
glass remains steady at 32 F. Explain.
6. Here in Tucson when it is hot outside, restaurants with outdoor seating often use misters to
make conditions more comfortable for their customers. Misters work by spraying a fine mist
of tiny water droplets into the air. How do misters cool the air? What happens to the
relative humidity of the air that is being cooled? Give two reasons why the relative
humidity changes the way that it does.
7. For this question, choose either the wind chill equivalent temperature or the heat index (not
both), and answer parts (a) through (c) below:
(a) Write a definition or otherwise explain the meaning of either wind chill or heat index
(b) If not part of your definition, list the two meteorological elements that are used to
determine a value for either the wind chill or heat index
(c) Explain how each of the two meteorological elements influences the value of the
wind chill or heat index.