Exam2_spring09

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ATMO 336 – Section 001
Exam 2 – Spring 2009
Name__________________________
Multiple Choice Section (2 points each)
Mark final answers on the multiple choice answer sheet. Please mark your answers clearly.
You must turn in the entire exam when finished.
1. When you touch a metal object that is at a temperature of 70° F it often “feels” colder compared to a
wooden object that is also at a temperature of 70° F. The best explanation for this is ________ .
(a) metal is a better heat conductor than wood (b) wood is a better heat conductor than metal
2. In Earth’s atmosphere, which type of convection transports energy from the surface and lower
troposphere to the middle and upper troposphere?
(a) Dry (natural) convection
(c) both (a) and (b)
(b) Moist convection
(d) neither (a) nor (b)
3. On a given day, the heat index in Phoenix is higher than it is in Tucson. Which of the following
MUST be true?
(a) The air temperature in Phoenix is higher than it is in Tucson
(b) The relative humidity in Phoenix is higher than it is in Tucson
(c) The dew point temperature in Phoenix is higher than it is in Tucson
(d) None of the above
4. When raising and lowering parcels in the atmosphere, within the air parcel, which of the following is
assumed to instantaneously adjust to match the environmental air outside the parcel?
(a) Pressure
(c) Number density
(b) Temperature
(d) Mixing ratio
5. Which general cloud type is most likely to form when the atmosphere is stable?
(a) Cumuliform type
(c) Stratiform type
(b) Clouds will not form when the atmosphere is stable
6. On a sunny day, at which altitude would you expect to find the largest change in air temperature
between sunrise and late afternoon?
(a) Air just above the ground (c) Air near top of the troposphere
(b) Air at 500 mb
(d) Air temperature change should be same everywhere
7. The Hawaiian Islands are an isolated island chain located in the warm waters of the tropical Pacific
Ocean near 20 North latitude. At the surface almost constant trade winds blow year round. Each
island has mountains near its center. This geography and prevailing winds cause two distinct climate
zones to be found on each island: a rain forest-like climate on one side each island and a desert-like
climate on the opposite side. Which side (quadrant) of the island will be the rainy side?
(a) Southwest
(b) Southeast
(c) Northwest
(d) Northeast
8. At what time of day would it be most likely to have a temperature inversion in the lower troposphere
that may cause problems by trapping pollution near the ground?
(a) The morning rush hour
(b) The evening rush hour
9. Consider an unsaturated, clear air parcel (one that does not contain a cloud) located 3000 m above sea
level. If this air parcel sinks down to sea level, the relative humidity of the air in the parcel _______ .
(a) will increase
(c) will not change
(b) will decrease
(d) may go up or down depending on other factors
10. An “Ice Storm” is associated with which type of precipitation?
(a) Hail
(b) Sleet
(c) Freezing rain
(d) Virga
11. In the Begeron process of precipitation formation, _________ shrink, while ________ grow large
enough to fall toward the ground.
(a) liquid cloud droplets ; ice crystals (b) ice crystals ; liquid cloud droplets
Fill in the table below by lifting an air parcel up from the surface to 5000 meters
above the surface, then answer questions 12 - 15.
Altitude
5000 m
4000 m
3000 m
2000 m
1000 m
0m
Environmental
Temperature
-11 C
-3 C
5 C
13 C
20 C
28 C
12. What is parcel temperature at 5000 m?
(a) -22 C
(b) -10 C
Parcel Temperature
Parcel Dew Point
Temperature
28 C
8 C
(c) -6 C
13. What is the parcel dew point temperature at 3000 m?
(a) 2 C
(b) 6 C
(c) 8 C
(d) -2 C
(d) 18 C
14. Where will a cloud begin to form in the parcel as it is being lifted?
(a) As the parcel moves above 1000 m (c) As the parcel moves above 3000 m
(b) As the parcel moves above 2000 m (d) As the parcel moves above 4000 m
15. Does the parcel become unstable? If yes, what is the lowest altitude in table where parcel is unstable?
(a) No
(c) Yes, at 4000 m
(b) Yes, at 3000 m
(d) Yes, at 5000 m
For each question 16-18, select the change that will act to make the atmosphere
more stable, i.e., decrease the likelihood of thunderstorms.
16. (a) Warm the air in the lower troposphere (near the ground)
(b) Cool the air in the lower troposphere (near the ground)
17. (a) Warm the air aloft (above 600 mb)
(b) Cool the air aloft (above 600 mb)
18. (a) Decrease the dew point temperature of the air aloft (above 600 mb)
(b) Decrease the dew point temperature of the air in the lower troposphere (near the ground)
19. On average, which area of the US experiences the fewest number of thunderstorms per year?
(a) West coast (California, Oregon, Washington)
(b) Desert southwest (Arizona, New Mexico, southern Colorado, southern Utah)
(c) Gulf coast (Florida, Alabama, Mississippi, Louisiana)
(d) Southern great plains (northeast Texas, Oklahoma, Kansas)
20. Suppose you do a stability analysis of the atmosphere by filling out a table (as done above for
questions 12-15) and you find that the atmosphere is unstable from 2000 – 8000 meters altitude. Does
this guarantee thunderstorms will occur? If not, what else is necessary?
(a) Yes
(c) No, the sun must be shining early in the day
(b) No, must be vertical wind shear
(d) No, needs to be a mechanism that lifts air to 3000 m
21. In the idealized life cycle of a single cell thunderstorm, the mature stage is characterized by _______ .
(a) updrafts
(c) neither (a) nor (b)
(b) downdrafts
(d) both (a) and (b)
22. What type of thunderstorm can often be identified by the presence of a dome cloud?
(a) An ordinary single-cell thunderstorm
(c) A supercell thunderstorm
(b) A multi-cell cluster storm
(d) A squall line thunderstorm
23. Severe thunderstorms are more likely to form where there is _________ because this _________ .
(a) no vertical wind shear ; keeps updrafts and downdrafts separated
(b) no vertical wind shear ; forces updrafts and downdrafts to mix
(c) strong vertical wind shear ; keeps updrafts and downdrafts separated
(d) strong vertical wind shear ; forces updrafts and downdrafts to mix
24. The movement of an individual thunderstorm is most influenced by ________ .
(a) the large-scale wind pattern in the middle troposphere near 500 mb
(b) the large-scale wind pattern at the surface
(c) the jet stream wind pattern
(d) none of the above; thunderstorms often move about randomly
25. If you see lightning, then hear thunder 30 seconds later, the lightning was about ______ miles away.
(a) 15
(b) 10
(c) 6
(d) 3
26. Which of the following is the most accurate description of the principle of a lightning rod?
(a) Lighting rods have been used since the 1700s, but how they work is not known
(b) The rod acts to discharge the thunderstorm
(c) The rod intercepts the lightning and safely carries the current around the objects it protects
(d) Positive charge induced in the rod repels the approaching negative stepped leader
27. The presence of supercooled liquid water in cumulonimbus (thunderstorm) clouds is important in the
formation of _______ . (Select ALL that apply, i.e., choose more than one answer if needed)
(a) tornadoes
(b) lightning
(c) hurricanes
(d) hail
28. The most likely place in the world for a violent tornado to form is the southern great plains of the
United States (northeast Texas, Oklahoma, Kansas).
(a) True
(b) False
29. Which has the strongest winds?
(a) A Category 1 hurricane
(b) An EF1 tornado
(c) A Category 5 hurricane
(d) An EF5 tornado
30. Hurricanes rarely produce tornadoes after making landfall.
(a) True
(b) False
31. Most major hurricanes that hit the United States begin as tropical easterly waves that move off the
continent of ________.
(a) Europe
(b) Africa
(c) Asia
(d) South America
32. On average, which ocean basin produces the most hurricanes per year?
(a) Eastern North Pacific (off west coast of Mexico)
(b) Western North Pacific (near southeast Asia) where they are called typhoons
(c) North Atlantic Ocean
(d) Western South Pacific (near Australia) where they are called severe tropical cyclones
33. The strongest winds and heaviest rain are associated with which part of a hurricane?
(a) The eyewall
(b) The eye
(c) The spiral rain bands
(d) The outflow
34. On average in the U.S., the number of people who are killed by extreme weather events each year is
about the same as the number of people what are killed in vehicle accidents.
(a) True
(b) False
35. A vast majority of atmospheric scientists believe that global warming will result in a large increase in
both the number and intensity of future hurricanes in and near the tropics.
(a) True
(b) False
36. On average, which type of severe weather kills the most people each year?
(a) Hurricanes and Tropical Storms
(b) Thunderstorms, including tornadoes, lightning, hail, and wind
(c) Flash Flooding
(d) Heat and Cold Waves (exposure to extreme temperatures)
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ATMO 336 -- Section 001
Exam 2 – Answer sheet
Name ________________________
1.
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19.
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Short Answer Questions (8 Points Each)
For each numbered question (1-4), you must select and answer either (a) or (b). Make sure you answer all parts of each
question you select. Your answers should be concise. Points may be deducted for incorrect or unnecessary statements.
1. Select (a) or (b)
a. Explain why cold (low air temperature) and windy conditions are more stressful for the human body
than cold and calm (light wind) conditions? List two physiological responses the human body takes to
avoid hypothermia. Briefly explain how each works. Explain why wearing several layers of loose-fitting
clothing may help prevent hypothermia.
b. List two physiological responses the human body takes to avoid hyperthermia. Briefly explain how each
works. Explain why one of these responses will not work if the air temperature is extremely high.
Explain why one of these responses will not work if the relative humidity is extremely high.
2. Select (a) or (b)
a. What happens to the temperature of an air parcel as it moves upward in the atmosphere? Explain why
without using any numbers. As a parcel moves upward above a certain altitude, the rate at which the air
temperature in the parcel changes becomes different. What causes the rate of temperature change with
increasing altitude to become different above a certain altitude? Explain. Why is this important in
understanding how thunderstorms form?
b. During our monsoon season, the amount of water vapor in the lower atmosphere increases greatly, increasing
our chances for thunderstorms. On some mornings during the monsoon season the sky is mostly cloudy due to
clouds left over from storms the day before, while on other mornings the sky is clear and sunny. Assuming no
differences in the amount of water vapor in the lower troposphere, do you expect a better chance of
thunderstorms forming on days with cloudy mornings or days with sunny mornings? Explain why. To
receive full credit you must provide the sequence of steps leading to thunderstorm formation.
3. Select (a) or (b)
a. A thunderstorm develops about 20 miles east of Tucson. Although Tucson does not get any rain initially, strong
40 mph winds from the east move in about a half an hour after rain began to fall from the thunderstorm to the
east. What is the cause of the strong winds in Tucson? Be sure to fully explain how the strong winds
develop. A short time after the thunderstorm to the east began to produce rain, another thunderstorm about 20
miles west of Tucson began to produce rain. About 45 minutes after the two thunderstorms surrounding
Tucson began raining, a new thunderstorm started to develop directly over Tucson. Explain how the two
original thunderstorms may have acted to initiate the new thunderstorm over Tucson.
b. As described in lecture, supercell thunderstorms, which may produce violent tornadoes, sometimes form over
tornado alley on days when the winds overhead come from three distinct sources:
 Lower Troposphere: Southeast winds transport warm, humid air from the Gulf of Mexico
 Middle Troposphere: Southwest winds transport hot, dry air from the Mexican highlands
 Upper Troposphere: Northwest winds transport cold air from Canada
Based on this information, point out some conditions that make the atmosphere favorable for the formation of
supercell thunderstorms and tornadoes. The hot, dry air flow in the middle troposphere places a “convective cap” or
“inversion layer” in the vertical temperature profile. What is a “convective cap”? How does the presence of the
“convective cap” contribute to the development of violent supercell thunderstorms?
4. Select (a) or (b)
a. Explain why inflation-adjusted hurricane property damages in the United States could very easily
increase in the future even if there is no change in the number or intensity of hurricanes that strike the
United States. Briefly discuss a few measures that could be taken to avoid higher losses in the future.
b. The first named tropical storm in the 2009 Atlantic hurricane season will be Ana. Assume Ana is a category 1
hurricane and is positioned as shown in the figure on page 4 of this exam (after the multiple choice questions).
The 24 hour forecast is for the Ana’s eye to make landfall near Brownsville, TX, which is close to the
Texas/Mexico border, as a category 2 hurricane. The hatched area on the coast indicates the land areas where
hurricane force winds are expected to occur. The area on land between the two W’s marks the coastal areas that
are put under a hurricane warning by the National Hurricane Center. Why is the hurricane warning area
much larger than the area forecasted to get hurricane force winds? Assuming that the hurricane does
make landfall exactly where predicted, where would you expect that the most damage will be done? Fully
explain the reason for your answer. Based on the current state of hurricane forecasting, discuss the
possibility of the storm becoming a category 5 hurricane before hitting the coast?
ATMO 336 – Section 001
Exam 2 – Short Answer Sheet
Name__________________________
Question #1. Please select and answer either part (a) or (b).
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Question #2. Please select and answer either part (a) or (b).
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Question #3. Please select and answer either part (a) or (b).
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Question #4. Please select and answer either part (a) or (b).
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