Salt Lake Community College
Geography 1000 – Physical Geography
AJ Allred, Spring 2015
Student Name ___________________
Quiz 3 for Chapter 3
Explanations
1. Nitrogen is _____________________.
a. mostly useless in the atmosphere
b. vital to human life on Earth
c. often part of photochemical smog and other air pollution
d. vital to explosives, rocket fuel and plant food
e. All of the above.
Nitrogen is a natural element that is found as a molecular pair (N2) in the atmosphere. In the
atmosphere, molecules of nitrogen are mostly inert. However, if chemical reactions are strong enough,
nitrogen can bond with oxygen to form an oxide that is part of photochemical smog and other air
pollution. Oxides of nitrogen include N2O, NO2 and NO. These compounds tend to be corrosive and
play a role in atmospheric heating.
Some compounds of nitrogen are useful in medicine, and fuels for engines. Nitrogen is vital to plant
growth and is one of the “big three” plant fertilizers – NPK. Nitrogen must be “fixed” by plants or other
means for it to become useful in soil.
2. Ozone is corrosive and noxious no matter where it is found, including ozone that is made by
nature and which protects us from dangerous ultraviolet solar rays.
True ____
False ____
Ozone is a molecule made of three oxygen atoms and has an atomic mass of 48 (Oxygen atoms weigh
16 each). Ozone is noxious and corrosive to living creatures and to many products. Therefore, groundlevel ozone is a part of air pollution, including photochemical smog. Ground-level ozone has many
causes, some natural, but is mostly a function of air pollution interacting with sunshine and summertime
heating near Earth’s surface.
Meanwhile, atmospheric ozone is created and destroyed by incoming solar energy in the “ozone layer”
found several miles above Earth’s surface. The result is that 95% of incoming ultraviolet solar energy is
absorbed by the atmospheric ozone in the “ozone layer”. Ultraviolet (Uv) energy that is trapped or held
in the ozone layer is thus not available to heat the Earth’s surface. Uv energy that does reach the Earth’s
surface tends to cause health problems and degrades or corrodes many substances.
So, solar energy is responsible for the creation of the ozone layer that is located several miles above the
Earth’s surface. Solar energy also plays a role in the creation of ground-level ozone during hot summer
days when ultraviolet rays combine with air pollution in the form of oxides of nitrogen and sulfur.
The explanation for Question 1 above includes the fact that high-temperature combustion, mostly by
motor vehicles and industrial plants, produces vast quantities of nitrogen oxides. This form of air
pollution is corrosive and acidic, especially when it involves sulfur. These oxides combine with
sunshine during hot weather to create yet another form of air pollution – ground-level ozone.
3. Based on simple interpolation, atmospheric pressure should be about 7.3 pounds per square
inch at 18,000 feet above sea level and about 4.9 pounds per square inch at the top of Mt.
Everest. At sea level, air should press on our bodies with a combined force of thousands of
pounds.
True ____
False ____
Earth’s atmospheric pressure varies widely from place to place and hour to hour. On a hypothetically
normal day, air pressure should be about 1,013mb or 14.7 pounds per square inch at sea level. So, with
the useful atmosphere being about 100 miles thick, we can say that the weight of 100 miles of air
pressing down on the Earth’s surface is worth a bit less than 15 pounds of pressure on each square inch
of surface area of any object located at sea level. Our bodies have hundreds of square inches of surface
area, so total atmospheric pressure will total thousands of pounds.
Air pressure diminishes sharply with altitude, so that air pressure at 18,000 feet is only about half of sea
level air pressure. At the top of Mt. Everest (29,000 feet above sea level) air pressure is down to about
1/3 of sea-level air pressure, or a little less than five pounds per square inch.
4. Chlorofluorocarbons (CFCs) are inexpensive and very useful products that make our lives
easier and more productive. CFC chemicals are not very toxic to people, and they help destroy
ozone that is noxious and corrosive. In spite of all these good things, we should avoid using
CFC chemicals.
True ____
False ____
Until recent years, CFC chemicals were found in countless products in use every day. One CFC
molecule can destroy thousands of molecules of atmospheric ozone, resulting less ozone available to
absorb hazardous ultraviolet (Uv) energy coming from the Sun.
Production and use of most CFC chemicals has been banned by international agreement; however, CFC
molecules persistent for decades in the atmosphere and continue to destroy the Earth’s protective ozone
layer. Gradual re-building of the ozone layer is expected over the next 100 years as CFC products
gradually decay.
All ozone is noxious to plants and animals and all ozone can be destroyed by CFC chemicals.
Fortunately, we are not exposed to useful atmospheric ozone that is located far from Earth’s surface.
Ground-level ozone is a hazard due to its proximity to plants, animals and products that can be damaged
or degraded by ozone.
5. Atmospheric pollution is not a concern for human health until it reaches about what portion of
the entire atmospheric mass?
a. Less than one half of one percent
b. More than 3.0 percent
c. More than 5.0 percent
d. More than 15.0 percent
e. According to the textbook, there is no way to know without more research
Many forms of hazardous air pollution become a threat to human health at levels of just a few parts per
million. Generally, air pollution becomes hazardous, and may trigger an air alert when even the
combined total of all types of pollution is still far less than one percent of atmospheric weight or
volume.
6. Coriolis force ____________________.
a. explains why water spirals down a sink or drain
b. is weak or non-existent near the north and south poles
c. causes flying objects to deflect to the left in the northern hemisphere
d. is one factor that causes the United States to host at least 90% of the world’s tornadoes
e. affects air movement, but not ocean currents
Water flowing down a sink or drain is too small and too brief to be affected by Coriolis force or effect.
Coriolis effects are stronger with latitude: there is a positive correlation between increasing latitude and
increasing Coriolis effect. Thus there is little or no Coriolis effect near the Equator.
In the northern hemisphere, Coriolis causes object in free flight (and ocean currents) to deflect to the
right, as viewed from above.
Although a tornado is too small and too brief to be directly affected by Coriolis force, the mid-latitude
cyclonic storms that provoke tornadoes are strongly affected by Coriolis force. The faster winds blow in
a storm, the more Coriolis deflects winds to the right (to the left in the southern hemisphere). At least
90% of the world’s tornadoes occur in the United States.
7. The six major elements of weather and climate include.
a.
b.
c.
d.
e.
Temperature, wind and crop growth
Crop growth (farm plants), humidity and length of day
Length of days (growing season), temperature and crop growth
Air temperature, humidity, wind and precipitation
All of the above are part of the “Big Six” topics in weather and climate
Temperature, air pressure, wind speed and direction, humidity, clouds, precipitation.
8. The lights are on in this classroom because of solar radiation stored in dead plants and animals.
True ___
False ___
In the United States, most electricity is produced by power plants using some form of fossil fuel: coal,
oil or natural gas. These fuels were formed over millions of years by heat and geologic pressure on beds
of dead plants and animals.
As a general rule, the older the fossil fuel the more it probably metamorphosed from remains of plants
and animals to fuel. For instance, a pile of dead leaves will eventually compost into a crude fuel or soil
amendment for growing new plants. Left alone for hundreds or thousands of years, compost will
convert into peat, a more concentrated and energetic fuel. Over millions of years, these organic beds
turn into low-grade lignite or “brown” coal. Over hundreds of millions of years coal becomes more
concentrated or pure (anthracite or bitumen). In general, crude oil is an even more pure or concentrated
fossil fuel and natural gas is the penultimate fossil fuel, containing only simple molecules of carbon and
hydrogen (CH4). Not surprisingly, the energy value, convenience and cleanliness of natural gas
surpasses all other fossil fuels.
9. Places near the ocean tend to have milder climates because nearby ocean water readily absorbs
heat during summer and releases that heat during colder weather. Ocean influence may not
help as much if wind blows the wrong way most of the time.
True ____
False ____
Water is chemically adept at absorbing energy: its color, clarity and physical nature allow it to absorb
vast amounts of solar energy and thermal energy from any source. As a result, places near oceans and
large lakes will tend to be cooler during hot weather and warmer during cold weather because water
absorbs and releases energy steadily year-round.
In contrast, land masses have relatively little ability to absorb thermal and solar energy, so temperatures
rise and fall rapidly, even from day-to-day. In places where wind prevails from the land, temperatures
will vary more widely as air temperature follows ground temperature, rising and falling quickly each day
and across seasons.
In contrast, sea level locations near the Equator are so mild that small daily temperature swings are
actually greater than annual average temperature swings. Mr. Allred’s general rules of climate apply:
the closer you are to ocean, sea level and the Equator the milder your weather and climate will be. To
the extent that winds prevail from the ocean, conditions are even milder.
10. In Utah, the longest day of the year is about June 21. The hottest day occurs in late July
because _______________________.
a. ground-level ozone in summer prevents solar energy reaching the Earth until July
b. the sun is too far north in June to help Utah. Only in late July does the Sun come back down
from the north far enough to raise Utah air temperature back to normal.
c. it takes a long time for warm weather to melt snow and heat large bodies of water. Even in
June, the northern hemisphere still hasn’t warmed-up fully from winter.
d. The Utah legislature enacted daylight savings time to ensure that hot weather does not occur
until school is out for the summer.
e. All of the above are essential for determining Utah’s hottest days of the year.
In the northern hemisphere, the Sun reaches its highest noon-time elevation in the sky on about June 21,
the longest day of the year. In Utah, the Sun will never be straight-up overhead, but does provide as
much as 15 hours of daylight at the summer solstice and as little as nine hours of daylight six months
later on the shortest day of the year, December 21.
Ground-level ozone plays no significant role in day-time temperatures.
Though June 21 is the longest day of the year in the northern hemisphere, temperatures do not peak until
July or early August because water bodies and land masses are still gradually warming-up from the
previous winter season.
The same is true on the shortest day of the year in Utah, the winter solstice on about December 21.
Earth and water masses have not yet lost all of the heat that they stored during the previous summer.
The coldest days of the year are typically in January: day length has increased only slightly, but more
time has passed for earth and water to lose the remainder of heat they absorbed during the previous
warm season.
Daylight savings time does not affect what days are highest or coldest anywhere.
The Sun is never too far north in Utah to prevent daytime heating. The opposite is true: in the depth of
winter, solar energy reaching Utah is much less than during summer.
11. Land masses heat up and cool down very quickly. Oceans and large lakes have such enormous
capacity to hold heat that it takes all summer for water temperature to change very much. As
a result ___________________________.
a. living near an ocean beach makes it easy to experience hypothermia and heat stroke
b. people are moving to coastal regions in spite of coastal hazards such as occasional
hurricanes, floods and landslides
c. climograph temperature profiles are very steep for places near the ocean
d. it is easier to get sunburned at the beach than further inland
e. All of the above.
Living near an ocean or large lake tends to provide relative mildness, as water absorbs heat during hot
weather and releases heat during cold weather. The interior of continental land masses exhibit relatively
more severe weather, as dry land overheats quickly in summer, radiating thermal energy back into space.
That is why an asphalt parking lot can be so uncomfortable: thin, dark surfaces quickly reach their
maximum absorption of solar energy and begin radiating that thermal energy out to nearby objects.
In contrast, clear water can absorb vast amounts of energy deep within its depth and volume. Being a
fluid, water can move that heat convectively and conductively, thus providing an almost infinitely vast
mass for collecting energy, while barely changing temperature.
Much of the world’s population resides near oceans, for a variety of reasons. Milder year-round
temperatures is a major attraction, compared to severe weather and vast swings in temperature that occur
in the middle of large continents that are isolated from the moderating effects of water. Consider again
“Mr. Allred’s Climate Rules” as described in the explanation Question .9 above.
12. During the next few weeks, there will be at least one day during which the entire Earth
experiences 12 hours of day and 12 hours of night.
True ____
False ____
Equinox means equal, as in equal length of days and nights. In March and September the days and
nights are about 12 hours each everywhere in the world. In December and June the solstice events
occur, when the lengths of days and nights are at their extremes. After the winter solstice, day length
begins to increase. After the summer solstice, day length begins to decrease. After each equinox day
length continues to increase or decrease as it was before the equinox arrived.
13. Combustion causes oxides that can be harmful. Which of the following elements form oxides
that affect atmospheric quality and/or create health and safety concerns?
a. Nitrogen
b. Carbon
c. Sulfur
d. Hydrogen
e. All of the above.
Oxides are formed when oxygen chemically bonds with any of several other elements. Water is
technically an oxide of hydrogen; carbon forms molecules of ‘monoxide’ and ‘dioxide’; sulfur and
nitrogen form oxides during high-temperature combustion.
Water vapor plays a vital, controlling role on Earth as it transfers energy, forms clouds and delivers
precipitation. Water is the most important way in which solar energy is transferred around the Earth and
is a controlling factor in all life forms and most land forms. Water is the single most powerful
atmospheric “greenhouse gas”.
Oxides of nitrogen and sulfur are corrosive and also help form another corrosive, noxious gas – groundlevel ozone. Carbon monoxide is a genuine poison, even at less than one percent concentration in air.
Carbon dioxide is the second most important “greenhouse” gas, after water vapor. The “greenhouse
effect” controls nearly all life on Earth.
14. The hydrosphere plays an important role in all of the other spheres. Atmospheric water tends
to _______________.
a.
b.
c.
d.
e.
make people feel worse during hot weather
make people feel worse during cold weather
provide a screen against powerful solar rays
be a major player in storms that kill thousands of people worldwide each year
All of the above are true.
When air is hot and humid, people are less able to cool by evaporation because air is already close to
saturation and cannot convert liquid to vapor effectively. Also, air that is hot and humid is more like
being immersed in genuine hot water, because water in the air contains a vast amount of heat. Heat
exhaustion can result.
When air is already cold, high humidity is not only uncomfortable but can cause hypothermia, or
excessive loss of body temperature. Water so easily absorbs energy from any source, that cold, wet air
is like putting your hand in a bucket of ice water - - the water quickly absorbs body heat.
Water vapor that condenses into cloud cover helps cool the Earth below. Water vapor is the cause of
severe storms, by absorbing and moving vast amounts of energy. Evaporation of water requires the
conversion of vast energy into latent form. With condensation, that stored energy is released. The most
powerful storms on Earth are a direct function of how much energy has been stored in water when it
evaporated from liquid to vapor.
15. Driving even the cleanest fuel cars (including electric cars) results in vast amounts of air
pollution that causes health problems and may be causing the entire Earth to become warmer.
True ____
False ____
All automobiles consume energy. Even electric cars rely mostly on power plants that burn fossil fuels.
In fact, the conversion of fossil fuel to electricity and its delivery to a charging station results in vast loss
of energy in conversion and transit. So, electric cars may cause little or no air pollution in their place of
use, but they do result in large amounts of air pollution in places where the electricity was generated.
In addition to air pollution, production of greenhouse gases is allegedly the cause of climate change that
may affect the quality of life for most of the world’s population.