Download Answer Key to AT350 Exam 2

AT 350
EXAM #2
March 25, 2008
This exam covers Ahrens Chapters 3 through 6, plus related lecture notes
Write the letter of the choice that best completes the statement or answers the question.
_A__
_A__
_E__
_B__
_A__
_B__
_B__
_C _
__B_
1. As the air temperature increases, with no addition of water vapor to the air, the dew point will:
a. remain the same
b. increase
c. decrease
d. increase and become equal to the air temperature
2. Suppose saturated polar air has an air temperature and dew point of -10o C, and unsaturated
desert air has an air temperature of 35o C and a dew point of 10o C. The desert air
contains __________ water vapor and has a __________ relative humidity than the polar air.
a. more, lower
b. more, higher
c. less, lower
d. less, higher
3. On a clear, calm, night, the ground and air above cool mainly by this process:
a. evaporation
b. reflection
c. convection
d. conduction
e. radiation
4. During the course of a year the sun will disappear from view near the North Pole on what date?
a. June 21
b. September 23
c. December 23
d. January 1
e. March 21
5. The processes of condensation and freezing:
a. both release sensible heat into the environment
b. both absorb sensible heat from the environment
c. do not affect the temperature of their surroundings
d. do not involve energy transport
6. The change of state of ice into water vapor is known as:
a. deposition
b. sublimation
c. melting
d. condensation
e. crystallization
7. The temperature to which air must be cooled in order to become saturated is the:
a. minimum temperature
b. dew point temperature
c. wet-bulb temperature
d. freezing point
8. Air that rises always
a. contracts and warms
b. contracts and cools
c. expands and cools
d. expands and warms
9. The change of state of ice into water vapor is known as: [OOPS: Duplicate question!]
a. deposition
Exam form A
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AT 350
_A__ 10.
_E__ 11.
_A__ 12.
_D__ 13.
__C_ 14.
_E__ 15.
_B__ 16.
EXAM #2
March 25, 2008
b. sublimation
c. melting
d. condensation
e. crystallization
As the air temperature increases, the air's capacity for water vapor:
a. increases
b. decreases
c. remains constant
d. is unrelated to air temperature and can either increase or decrease
The north-facing side of a hill in a mountainous region in the US tends to:
a. receive less sunlight during a year than the south-facing side
b. grow a variety of trees that are typically observed at higher elevation
c. be a better location for a ski run than the south-facing side
d. have snow on the ground for a longer period of time in winter compared to the southfacing side
e. all of the above
During the afternoon the greatest temperature difference between the surface air and the air several meters
above occurs on a:
a. clear, calm afternoon
b. clear, windy afternoon
c. cloudy, calm afternoon
d. cloudy, windy afternoon
The heat energy released when water vapor changes to a liquid is called:
a. latent heat of evaporation
b. latent heat of fusion
c. latent heat of fission
d. latent heat of condensation
If a glass of water were surrounded by saturated air:
a. the level of the water in the glass would slowly decrease
b. the water's temperature would slowly increase
c. the level of the water in the glass would not change
d. the water's temperature would slowly decrease
The main reason(s) for warm summers in middle latitudes is that:
a. the earth is closer to the sun in summer
b. the sun is higher in the sky and we receive more direct solar radiation
c. the days are longer
d. all of the above
e. only (b) and (c) are correct
Which of the following will increase in a rising parcel of air?
a. saturation vapor pressure
b. relative humidity
c. mixing ratio
d. air temperature
e. none of the above
Exam form A
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AT 350
EXAM #2
March 25, 2008
_B__ 17. In the Northern Hemisphere, this day has the fewest hours of daylight:
a. summer solstice
b. winter solstice
c. vernal equinox
d. autumnal equinox
_C__ 18. If the air temperature increased, with no addition or removal of water vapor, the actual vapor pressure would:
a. increase
b. decrease
c. stay the same
d. become greater than the saturation vapor pressure
_B__ 19. The only substance near the earth's surface that is found naturally in the atmosphere as a
solid, liquid, and a gas:
a. carbon dioxide
b. water
c. molecular oxygen
d. ozone
e. carbon
_D__ 20. If the air temperature in a room is 70o F, the saturation vapor pressure is 25 mb, the dew point temperature is
45o F, and the actual vapor pressure is 10 mb, then the relative humidity must be near __________ percent.
a. 15
b. 20
c. 35
d. 40
_B_ 21. In most areas the warmest time of the day about 5 feet above the ground occurs:
a. around noon
b. in the afternoon between 2 and 5 pm
c. in the early evening after 6 pm
d. just before the sun sets
__E_ 22. Over the earth as a whole, one would expect to observe the smallest variation in temperature from day to day
and from month to month:
a. at the North Pole
b. in the center of a large land mass
c. along the Pacific coast of North America
d. high in the mountains in the middle of a continent
e. on a small island near the equator
_B_ 23. An example of orographic clouds would be:
a. clouds forming over a warm ocean current
b. clouds forming on the windward slope of a mountain
c. clouds forming behind a jet airplane
d. clouds formed by surface heating
_B__ 24. If a parcel of unsaturated air with a temperature of 30o C rises from the surface to an altitude of 1000 m, the
unsaturated parcel temperature at this altitude would be about:
a. 10o C warmer than at the surface
b. 10o C colder than at the surface
c. 6o C colder than at the surface
d. impossible to tell from the data given
Exam form A
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AT 350
EXAM #2
March 25, 2008
_B__ 25. Which statement below best describes the curvature effect?
a. Large cloud droplets fall faster than small droplets
b. small droplets evaporate more quickly than large droplets
c. small droplets collide and coalesce more easily than larger droplets
d. explains the six-sided shape of ice crystals
_C__ 26. Condensation onto hygroscopic nuclei is possible at relative humidities less than 100 percent due to the:
a. curvature effect
b. electrical charge on these nuclei
c. solute effect
d. crystalline structure of these nuclei
__C_ 27. The dry adiabatic lapse rate is _________ greater than the moist adiabatic lapse rate.
a. never
b. sometimes
c. always
_A__ 28. Suppose it is a winter night and at about 11 pm the air cools to the dew-point temperature and a thick
radiation fog develops. If the air continues to cool during the night, in 5 hours the dew point temperature will
probably:
a. decrease as the air becomes drier
b. decrease as the air becomes moister
c. increase as the air becomes drier
d. increase as the air becomes moister
_A__ 29. Which cloud will have the highest base?
a. cirrostratus
b. cumulonimbus
c. altostratus
d. cumulus
_A__ 30. Dew is most likely to form on:
a. clear, calm nights
b. cloudy, calm nights
c. clear, windy nights
d. cloudy, windy nights
e. rainy nights
_A__ 31. The rate at which the actual air temperature changes with increasing height above the surface is referred to as
the:
a. environmental lapse rate
b. dry adiabatic rate
c. moist adiabatic rate
d. thermocline
_C__ 32. Particles that serve as surfaces on which water vapor may condense are called:
a. hydrophobic nuclei
b. nacreous nuclei
c. condensation nuclei
d. scud
____ 33. At the same sub-freezing temperature, the saturation vapor pressure just above a liquid water surface is
_________ the saturation vapor pressure above an ice surface.
a. greater than
b. the same as
c. less than
Exam form A
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AT 350
EXAM #2
March 25, 2008
_D__ 34. The difference between the "moist" and "dry" adiabatic rates is due to:
a. the fact that saturated air is always unstable
b. the fact that an unsaturated air parcel expands more rapidly than a saturated air parcel
c. the fact that moist air weighs less than dry air
d. the fact that latent heat is released by a rising parcel of saturated air
_D__ 35. On a clear, windy day, the depth to which mixing occurs above the surface depends upon:
a. the wind speed
b. surface heating
c. the landscape
d. all of the above
_B__ 36. A rising parcel of air that does not exchange heat with its surroundings is an example of
a. isothermal ascent
b. an adiabatic process
c. forced lifting
d. advection
_C _ 37. Which cloud type would most likely form in absolutely stable air?
a. cumulus congestus
b. cumulonimbus
c. stratus
d. altocumulus
_C__ 38. Cirrus clouds are composed primarily of:
a. water droplets
b. water vapor
c. ice particles
d. salt aerosols
_C__ 39. The dry adiabatic lapse rate results from a balance between:
a. Radiation and latent heating
b. Convection and the pressure gradient
c. Enthalpy and gravitational potential energy
d. Solute and curvature effects
__C_ 40. Atmospheric stability is enhanced by:
a. Cooling aloft or warming near the surface
b. Strong winds
c. Warming aloft or cooling near the surface
d. Condensation of cloud or fog droplets
_D__ 41. Cumulus clouds are more likely to form when:
a. The environmental lapse rate is less than moist adiabatic
b. A parcel is forced to rise as wind blows over a mountain range
c. Fog droplets fall as drizzle
d. The environmental lapse rate is greater than dry adiabatic
__A_ 42. Over the Sahara Desert:
a. Less solar energy is absorbed than escapes as longwave emissions
b. Fog is formed when evaporation exceeds precipitation
c. More solar energy is absorbed than is lost as longwave radiation
d. Salt crystals form on the ground
_B__ 43. Net accumulation of solar heating in excess of longwave cooling in the deep tropics is balanced by:
a. Latent heat of evaporation
b. Export of energy by winds and ocean currents
c. Heavy precipitation
d. Volcanic emissions
Exam form A
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