Download Geography 1000

Salt Lake Community College – Meteorology 1010
Mid-term Exam
J. Allred, Adjunct
Student Name: ____________________
1. Worldwide, what weather condition is likely to be the greatest killer of people in the near future:
a. Tornado
b. Flood
c. Hurricane
d. Atmospheric heat
e. Atmospheric cold
Tornado deaths in the United States are on the decline, and deaths due to flood and hurricane are declining as well, even
as property (dollar) loss due to natural hazards is rising. Periodic “heat waves” around the world in recent years have
killed tens of thousands of people. The trend is toward more heat. Many heat-related deaths go unreported.
2. Condensation forms on cool surfaces that reduce the adjacent air to the “dew” point.
True _X__
False ___
Any air that is cooled may reach the point of vapor pressure saturation, or ‘dew point’ wherein there is not enough heat in
the air to hold moisture in latent, or vaporized state. Warm air that contacts a cold surface, whether a pop can or a cold
lake, will tend to provoke condensation, as water droplets or fog.
3. X-rays and gamma rays exhibit very small wave lengths and small amplitudes but deliver a combined total of
more actual electromagnetic power or energy than do sunlight and infrared.
True ___
False _X__
X-rays are very small in amplitude and frequency and deliver relatively little of the total energy supplied by the
electromagnetic spectrum. In contast, infrared (as heat) and visible light are very energetic, and together supply more than
half of the electromagnetic energy supplied to the Earth from outer space.
4. Air that is descending will tend toward warming due to generally higher air pressure at lower elevation.
True _X__
False ___
Descending air will tend to be compressed by higher air pressure found at lower altitudes. Energy in the descending air
parcel will be concentrated by the compression, thus becoming warmer. Warmer air is more “thirsty” or more able to
hold moisture. Rising capacity to hold moisture makes it relatively less likely that water vapor will condense and
precipitate.
5. Generally, the quickest way to produce a cloud of condensed moisture is by:
a. Raising the temperature of the air parcel
b. Lowering the temperature of the air parcel
c. Compressing the air parcel
d. Taking the air parcel to a drier location
e. Taking the air parcel to a lower elevation
Moving air is subject to changing conditions as it moves. The universal requirement for condensation of moisture is that a
parcel of air cool down, whether by upward or side to side.
6. Which of the following parcels of air is most directly able to produce fog:
a. Descending air
b. Cyclonic, counter-clockwise air movement
c. Cooling air
d. Warming air
e. Air moving in a clockwise, or anti-cyclonic direction
7. An air mass can become unstable and then move, or can move and become unstable.
True _X__
False ___
Stable air can become unstable and therefore move, if temperature changes or moisture is added. Meanwhile, air that
moves can be subject to change because it is moving to a place where conditions provoke instability.
8. Chlorofluorocarbons help create atmospheric ozone. Atmospheric ozone helps keep the surface of the Earth
warmer.
True ___
False _X__
CFCs do not create Ozone; instead, they tend to destroy it. In any case, atmospheric Ozone (e.g. Ozone “layer”)
absorbs solar energy, thus reducing the amount of electromagnetic energy that can reach the surface of the Earth
9. What condition is most likely to result in reducing the risk of skin cancer:
a. Increasing industrial and automotive ground-level ozone that destroys CFCs
b. A world-class volcanic eruption of dust and water vapor
c. Emissions of carbon compounds containing fluorine and chlorine
d. Decreasing the amount of excess O3 in the atmospheric ozone layer
e. All of the above are helpful
A volcano can put enough aerosols (dust, dirt, vapor) into the atmosphere to provide a “sun screen” that blocks solar
energy from reaching the Earth’s surface. Depletion of the Ozone layer would tend to do the opposite.
10. When clouds form, heat is being absorbed and ‘hidden’ (latent), so temperatures drop.
True ___
False _X__
Condensation is evidence that an air parcel has reached vapor pressure saturation, or “dew point”. When water vapor
condenses the heat that was latent, or hidden, reappears as “sensible” heat, or energy that you can feel.
11. The term “Conduction” refers to the way energy moves by radiation between substances.
True___
False_X__
Conduction refers to transfer or energy by direct contact. Radiation is movement of electromagnetic energy across any
medium, including empty space.
12. Located at 40 degrees north latitude, Salt Lake City receives most of its weather from the West.
True _X__
False ___
Generally true; however, in summer Utah often receives water vapor from the South by “monsoon” conditions.
13. Rain is more likely to occur after moist air flows over the top of mountains and cools and condenses on its way
down the other side.
True ___
False _X__
Precipitation is provoked by cooling air that has decompressed by rising. Descending air should exhibit the opposite
effect.
14. Arizona is hotter than Hawaii because the sun shines more brightly in Arizona.
True ___
False _X__
Arizona has much drier conditions than Hawaii. As such, there is less cloud cover to reflect solar energy back into space
and less water vapor available to absorb heat.
15. For the Earth to avoid overheating, which of the following processes is most important:
a.
b.
c.
d.
e.
Conduction
Convection
Advection
Radiation
None of the above
The only way for solar energy to reach the Earth’s surface is by radiation, and the only way for heat to escape the Earth is
by radiation.
16. In a place with very wet air at 100° F there should be frost at a location 9,000 feet higher than that location.
True ___
False _X__
At an adiabatic rate of roughly three degrees (F) per thousand feet of increasing altitude, frost would not be encountered
below about 23,000 feet.
17. The daily weather news will report absolute humidity rather than percent vapor saturation.
True ___
False _X__
Weather reports focus on relative humidity, because the ratio of water vapor to vapor capacity determines whether clouds
form and precipitation occurs.
18. Which of the following options is/are represented by this generalized chemical relationship?
[H2O + CO2 + electromagnetic energy = HC + O2]
a. Green plant growth
b. Conversion of sunshine into a form that could someday become fossil fuel
c. A cooler planet than otherwise
d. Reduction in atmospheric carbon dioxide
e. All of the above
Green plant growth stores solar energy as hydrocarbons. Doing so also stores carbon dioxide.
19. All precipitation events fall into three categories: orographic, convective and convergent.
True ___
False _X__
Frontal, or wedge weather patterns are some of the most common and important in the United States and world-wide.
20. Severe surface heating can cause air to become unstable; however, cumulonimbus clouds and precipitation are
unlikely to occur if a great deal of moisture is present.
True ___
The opposite is true.
False _X__
21. The occurrence of virga should make the nearby surrounding air a little bit cooler than otherwise.
True _X__
False ___
Virga is rainfall that evaporates before reaching the ground. Evaporation is a cooling process, whereby heat becomes
latent, or hidden.
22. Lightning and thunder are caused by the sudden release of energy from the ground to a nearby cloud.
True ___
False _X__
Energy accumulates because of air movement associated with clouds and water vapor. The ground does not move; it just
receives the voltage that is stored in clouds.
23. A hurricane is an important means of preventing drought in Florida and Bangladesh.
True _X__
False ___
Tropical storms carry latent heat as moisture away from the equatorial zones, toward sub-tropical and mid-latitude areas
that need the water.
24. The presence of mountains can cause ordinarily stable air to become unstable.
True _X__
False ___
Air that is not humid enough or hot enough to become unstable on its own can become unstable when it is compelled to
rise when moving into rising terrain.
25. What two climate zones prevail in Utah:
a. A and B
b. B and C
c. D and H
d. B and H
e. E and H
“B” or dry climates prevail in Utah. Mountains are also common, hence the “H” designation (highland)
26. The rate at which air pressure decreases with altitude also decreases with altitude.
True _X__
False ___
Air pressure decreases with altitude. Most of the decrease occurs at lower elevations. At high elevations, there is little
remaining air pressure, so the rate of decreasing air pressure slows down as altitude increases. There is very little change
in air pressure from 20 to 100 miles above the Earth because there is very little atmosphere remaining at altitudes in that
realm.
27. In the northern hemisphere, the Coriolis force will help prevent tornadic conditions, such as tropical cyclones
and hurricanes that are so common at the Equator.
True ___
False _X__
The Coriolis force helps provoke tornadoes by causing air to move in curves or “twist” that provokes acceleration rather
than slower straight-line flow.
28. By itself, the world-wide system of Hadley cells ought to produce what climate zone in Georgia, Alabama and
Florida?
a. A
b. B
c. C
d. D
e. E
World-wide, there ought to be dry conditions at north and south ends of Hadley cells, where air is descending and
therefore compressing and warming. The Southeastern United States is an exception due to Trade winds that bring
moisture.
29. Which of the following is true about Utah weather in July?
a.
b.
c.
d.
e.
High atmospheric pressure is a dominant regional factor that promotes dry conditions
Dominant wind patterns are bringing monsoon conditions from the south
Daytime surface heating is setting-off local, small-scale low pressure events
Rising air results in rising humidity levels that can lead to unstable air mass conditions
All of the above are true
30. The “urban heat island” effect can pull cooler air from the countryside but can also concentrate air pollution
over big cities.
True _X__
False ___
Large downtown areas typical have many hard surfaces that heat up severely during warm days. The result is low
pressure from rising air. Cooler, higher pressure air from outside the city is then drawn in to fill the low pressure area.
This air movement is often not enough to remove accumulated air pollution.
31. The term “monsoon” refers to a strong seasonal reversal of wind from to and from continents and adjacent
oceans. A side effect is the potential for great variation in precipitation between seasons.
True _X__
False ___
The Utah/Arizona monsoon brings heat but may also “pull” in moisture from the Gulf and/or Pacific Ocean.
32. During summer, intense daily surface heating of continental interiors can produce rising air and instability.
True _X__
False ___
Warm air may exhibit low humidity until surface heating causes it to rise, decompress, and cool down. With enough
cooling, condensation and precipitation may occur, thus releasing more heat and causing more instability.
33. Clockwise, descending air masses tend to produce everything except:
a. Dry, warming conditions
b. Wet, rising air and precipitation
c. Stable, sometimes stagnant and hazardous air quality
d. Either cold or hot surface conditions
e. “B” climate
34. Cumulonimbus clouds result from atmospheric warming caused by descending air and rain.
True ___
False _X__
Rising air produces decompression, cooling and condensation. Descending air tends to warm up and dry out.
35. During a strong “El Nino” event, the easterly trade winds may not succeed in pushing warm equatorial water
away from South America, resulting in more-than-usual precipitation in parts of the Western Hemisphere.
True _X__
False ___
36. Air masses take on the characteristics of their source regions. They provoke storminess when they move to
other regions.
True _X__
False ___
Any time air masses move outside their source region, the warmer, wetter air mass will tend to rise and become unstable.
37. High latitude continental air masses tend to be more humid than maritime air masses.
True ___
False _X__
Maritime air is associated with oceans. Oceans evaporate water, thus making the atmosphere more humid.
38. During a “lake effect” storm, which community should receive the most snow or rain:
a. Park City
b. Bountiful
c. Wendover
d. Elko
e. All of the above should be affected more-or-less equally.
Bountiful is in the most direct path of air moving eastward across the Great Salt Lake. Such air picks up heat and
moisture from lake waters. Cooler conditions and mountains on the downwind side provoke instability and precipitation.
Park City is also downwind but on the drier, downward back side of the westerly flow.
39. Rising air tends to warm up because air pressure rises with altitude.
True ___
False _X__
Rising air tends to cool down because it encounters lower atmospheric pressure as it rises, thus causing it to expand and
de-concentrate the heat it is holding.
40. Humid air:
a. will tend to rise because it is less dense than dry air
b. is more likely to rise because it contains water
c. is more likely to be stable due to heaviness and latent heat
d. is more likely to prevent lightning by providing a conduit of dampness to the ground.
e. answers ‘a’ and ‘b’ above are both good
Water vapor has a lower atomic weight than dry air.
41. As a “frontal wedge” storm dissipates, warm air will be layered above cold air.
True _X__
False ___
Warmer air aloft is a temporary condition that exists after a colder wedge of air has pushed all the warm air to position
above the cooler air. Soon afterward, surface heating will cause lower altitudes to become warmer while air aloft cools
down from radiation loss.
42. If the United States followed the world’s typical climate pattern, then there should be dry or desert conditions
across Louisiana, Alabama and Florida.
True _X__
See notes to question #28
False ___
43. An “air mass” thunderstorm tends to be isolated and brief, caused by local variation in heating and humidity
that quickly extinguish themselves by their own down-drafts.
True _X__
False ___
Air mass thunderstorms represents mostly small-scale instability caused by localized surface heating and parcels of moist
air that are not as concentrated or widespread as that found in regions of persistent high humidity and high air
temperatures.
44. On a normal or ‘standard’ day, air pressure at 18,000 feet should be about:
a. 15 pounds per square inch (psi)
b. 1013 mb
c. 7.5 psi
d. Twice as much as at level
e. None of the above is a good estimate
At 18,000 feet, standard atmospheric conditions will exhibit a loss of about half of the typical air pressure found at sea
level. Standard sea level air pressure is about 15 pounds per square inch.
45. In a wind pressure map of a tornado, isobars will appear unusually far apart, showing a strong pressure gradient.
True ___
False _X__
In a tornado or other unstable condition, falling barometric pressure (not just low pressure) means that the pressure
gradient will cause moving air to accelerate, rather than just move at a steady speed. Decreasing distance between isolines
indicates falling air pressure, and thus increasing wind speed.
46. Tornadoes are more likely to occur when an entire region consists of uniformly warm, wet air with no
compensating cold, dry air to shut off cyclonic winds.
True ___
False _X__
Tornadoes depend on rapidly rising air, a condition that requires collision with an air mass that is more dry and more cold,
in order to provide more buoyancy for rising air to accelerate its instability.
47. Thunder is caused by rapid heating and expansion of air.
True _X__
False ___
Sudden expansion of air causes a shock wave that can be heard as sound
48. Across 400 miles at the same elevation, what kind of air pressure difference could be exhibited in association
with a major hurricane?
a. 350 mb
b. 500 mb
c. 1000 mb
d. 110 mb
e. five mb
Even a horizontal pressure difference of 50 mb represents a gradient steep enough to represent a severe storm. A vertical
pressure difference of 50 mb means relatively little by comparison.
49. Which factor below is not related to where and how hurricanes initially form:
a. Cold water above 50° N Latitude
b. Lack of Coriolis effect at the equator
c. High air pressure
d. Convective and convergent conditions
e. Trade winds
High atmospheric pressure are part of the rise and fall of air in severe storms; however, the initial formation of a hurricane
is governed much more by the other factors above
50. A “dry line” storm is usually mild, because it occurs in between a cold front and warm front and lacks moisture
needed for heavy precipitation.
True ___
False _X__
The “dry line” represents a general boundary between cooler, drier air that helps warmer, wetter air to become unstable
and rise relatively faster, thus provoking more instability. The contrast between air masses is the key to instability, and
instability is the key to severity. So, a dry line storm ought to be relatively more violent than otherwise.