CHAPTER 3
PLANETARY ENERGY BALANCE IN EARTH’S CLIMATE
SYSTEM
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MULTIPLE CHOICE QUESTIONS
1. What is the ultimate source of energy driving Earth’s climate system?
*a. the Sun
b. infrared radiation emitted by Earth
c. geothermal energy
2. Electromagnetic energy can be converted into __________ energy.
a. heat
b. kinetic
*c. Both of the above are correct.
d. None of the above is correct.
3. The wavelength of visible light ranges from about 0.40 to 0.70
*a. micrometers.
b. meters.
c. kilometers.
4. What statement is true of a blackbody?
a. a perfect absorber and perfect emitter of radiation
b. the wavelengths of emitted radiation are related to its temperature
c. surface of an object may approximate a blackbody only for certain wavelengths of radiation
*d. All of the above are correct.
e. Only b and c are correct.
5. The wavelength of most intense radiation emitted by a blackbody is __________ proportional
to its temperature.
a. directly
*b. inversely
6. According to Wien's displacement law, which one of the following objects emits its most
intense electromagnetic energy at the shortest wavelength?
a. an ice sheet
b. a stove
*c. the Sun
d. a tree
7. Solar radiation peaks in the __________ portion of the electromagnetic spectrum, whereas
radiation emitted by Earth’s surface peaks in the __________.
*a. visible…..infrared
b. infrared…..visible
8. The Stefan-Boltzmann law implies that a small change in the temperature of a blackbody
results in a(n) __________ change in the total amount of radiational energy emitted.
a. much smaller
b. equal
*c. much greater
9. According the inverse square law, tripling the distance traversed by radiation reduces its
intensity to __________ of its initial value.
a. one-half
b. one-third
c. one-fifth
*d. one-ninth
10. Due to the Moon’s rotational characteristics and absence of an atmosphere, the temperature
of the lunar equator exhibits a __________ temperature range than that observed on the Earth’s
equator.
a. much smaller
b. approximately equal
*c. much greater
11. Global radiative equilibrium implies that the total energy absorbed by Earth is __________
the total energy emitted by the Earth-atmosphere-ocean system.
a. less than
*b. equal to
c. more than
12. The ultimate source of solar radiation is
a. convection.
b. nuclear fission.
*c. nuclear fusion in the Sun.
d. sunspots.
e. solar tides.
13. Which of the following is true of sunspots?
a. relatively light, hot areas
b. dot the surface of the solar corona
*c. can influence changes in solar energy output and Earth’s climate
d. All of the above are correct.
14. Today, the solar altitude is at a maximum around
a. sunrise.
b. 6 pm.
*c. noon.
d. 9 am.
e. sunset.
15. Earth is farthest from the Sun during the
a. Northern Hemisphere winter.
*b. Northern Hemisphere summer.
c. Southern Hemisphere spring.
d. Southern Hemisphere fall.
e. Southern Hemisphere summer.
16. Earth is closest to the Sun in
*a. January.
b. April.
c. July.
d. October.
17. During winter in the Northern Hemisphere, the number of hours of daylight is __________
the number of hours of darkness.
a. equal to
b. greater than
*c. less than
18. During __________ in the Southern Hemisphere, the number of hours of daylight is greater
than the number of hours of darkness.
a. winter
*b. summer
19. Exactly one-half of the surface area of the Earth is in sunlight during
a. either equinox only.
b. the winter solstice only.
c. the summer solstice only.
*d. any day of the year.
e. 1 January.
20. Earth's rotational axis is oriented perpendicular to the Sun's rays on the first day of
*a. fall.
b. winter.
c. summer.
d. All of the above are correct.
e. None of the above is correct.
21. On the first day of summer in the Northern Hemisphere, the noon Sun has an altitude of 90
degrees where?
*a. Tropic of Cancer
b. Arctic Circle
c. Tropic of Capricorn
d. Antarctic Circle
e. the equator
22. Except right at the poles, on the Earth nights are about 12 hours long when?
a. aphelion
b. perihelion
*c. equinoxes
d. solstices
e. 1 July
23. At the equinoxes, the noon Sun has an altitude of 90 degrees at the
a. north pole.
*b. equator.
c. Tropic of Capricorn.
d. Arctic Circle.
e. Tropic of Cancer.
24. Which location has the greatest change in daylight period over the course of a year?
a. equator.
b. Tropic of Capricorn.
*c. Arctic Circle.
d. Tropic of Cancer.
25. Earth's solar constant
*a. is actually variable.
b. refers to the intensity of solar radiation that reaches the lower troposphere.
c. is about 10 calories per square centimeter per minute.
d. must be measured on the summer solstice.
e. must be measured on the winter solstice.
26. The __________ Hemisphere has a greater percentage of surface area covered by ocean,
a. Northern
*b. Southern
27. As solar radiation travels through the atmosphere, a portion of that radiation is
a. absorbed by gases.
b. reflected by clouds.
c. scattered by dust particles and molecules.
*d. All of the above are correct.
e. None of the above is correct.
28. According to the law of conservation of energy, the sum of absorptivity, albedo, and
transmissivity equals
a. 25%.
b. 50%.
c. 75%.
*d. 100%.
29. Through which process is some of the radiation striking an object converted to heat energy?
a. scattering
b. reflection
*c. absorption
d. albedo
e. transmissivity
30. The layer of the atmosphere that contains the ozone shield is the
a. troposphere.
*b. stratosphere.
c. mesosphere.
d. thermosphere.
31. The principal threat to the ozone shield is (are)
*a. chlorofluorocarbons (CFCs).
b. automobile exhaust.
c. burning of fossil fuels.
d. volcanic eruptions.
e. global warming.
32. The Antarctic ozone hole occurs during the Southern Hemisphere
a. winter.
*b. spring.
c. summer.
d. fall.
33. Which one of the following surfaces has the highest albedo for visible solar radiation?
a. ocean water
b. sand
*c. fresh snow
d. tropical rainforest
e. old snow
34. Which cloud type has the greatest average albedo?
a. cirrus cloud
b. stratocumulus cloud
*c. cumulonimbus cloud
35. The average albedo of the ocean is
a. greater than that of clouds.
b. greater than Earth's planetary albedo.
*c. less than 10 percent.
d. about 30 percent.
e. more than 60 percent.
36. Over the course of a day, the albedo of the sea surface
a. stays about the same.
*b. varies greatly.
37. Within clear, clean water __________ light penetrates to the greatest depth.
a. red and orange
b. yellow
*c. green and blue-violet
38. If more solar radiation is absorbed than emitted at the Earth’s surface, then the temperature of
surface will
*a. rise
b. fall.
c. not change.
39. The principal absorber(s) of the solar radiation that is intercepted by the Earth-atmosphere
system is (are)
*a. ocean water
b. land
c. clouds
40. The albedo of the Earth is __________ that of the Moon.
*a. greater than
b. less than
41. The troposphere is primarily warmed by
a. absorption of solar radiation by clouds.
b. scattering of solar radiation by aerosols.
*c. heat transferred from Earth’s surface.
d. absorption of solar radiation by ozone.
e. heat transferred from the mesosphere.
42. The greenhouse effect is primarily the consequence of atmospheric
*a. water vapor.
b. nitrogen.
c. oxygen.
d. ozone.
e. carbon dioxide.
43. At night, air temperatures near Earth’s surface tend to be highest when the sky is
*a. completely cloud covered.
b. partly cloudy.
c. clear.
44. At about the same latitude, a location __________ would likely have the greatest diurnal
temperature range.
a. along the Gulf Coast
*b. in the Desert Southwest
45. In accordance with the Callendar effect, the chief reason for the upward trend in atmospheric
carbon dioxide since the mid-1800s is (are)
*a. burning of fossil fuels.
b. deforestation.
c. less photosynthesis worldwide.
d. volcanic eruptions.
e. the ozone hole.
46. During which 10-year period was the growth of atmospheric carbon dioxide the greatest?
a. 1948-1957
b. 1968-1977
c. 1988-1997
*d. 1998-2007
47. Methane and nitrous oxide have __________ values on the global warming potential (GWP)
index.
a. low
*b. high
48. A change in __________ could shift Earth to a new radiative equilibrium.
a. solar constant
b. planetary albedo
c. emissivity
*d. All of the above are correct.
e. None of the above is correct.
49. An increase in the solar constant would lead to a __________ radiative equilibrium
temperature.
a. lower
*b. higher
50. The Earth-atmosphere-ocean system would respond to an increase in planetary albedo by
emitting __________ intense IR radiation to space.
*a. less
b. more