Salt Lake Community College
Geography 1700 – Physical Geography
AJ Allred, Spring, 2015
Student Name ___________________
Quiz 6
1. Kinetic energy is substance or mass in motion. Typically, kinetic motion is felt as heat that we can
also measure as temperature.
True ___
False ___
Molecular motion varies positively with energy content. We can measure kinetic motion as sensible heat
(temperature).
2. A small increase in ocean temperature represents enough additional energy for a hurricane that is
more powerful than a nuclear bomb.
True ___
False ___
Water has more “specific heat capacity” than almost any other substance, so ocean water shows very little
temperature change even after absorbing vast amounts of energy. That energy can be absorbed from the ocean
and then released through evaporation that “fuels” severe storms.
3. Tornado strength is measured on a scale based on _____________.
a.
b.
c.
d.
e.
wind speeds categories from 1 to 10
air pressure that ranges from 850 mb to 1013 mb
Saffir Simpson categories 1 to 5
wind speed categories from EF 0 to EF 5
None of the above is the correct scale for measuring tornado strength or size
The Enhanced Fujita (EF 0 to 5) system is based on wind speed that is estimated based on damage.
4.
Of all solar energy absorbed by Earth’s oceans and dry land, about how much is probably absorbed
by oceans alone?
a.
b.
c.
d.
e.
At least 35%
About 20%
At least 69%
About 45%
There is no way to know because Earth’s oceans are too big for measurement
Based on classroom discussion, Earth’s surface absorbs 45% percent, and oceans cover 70% of that surface.
So, 0.45 x 0.70 = at least 35% of Earth’s total solar budget.
.
5. Convective and conductive flow help Earth’s thermal energy escape the atmosphere so that overheating does not occur.
True ___
False ___
Convection and conduction are the movement of energy in mass or substance. There is virtually no substance
in outer space, so energy cannot leave the Earth except by radiation.
6. The world’s oceans transfer energy by _____________
a.
b.
c.
d.
e.
conduction
convection
radiation
reflection
All of the above
True ___
False ___
Ocean water moves (convection) and can transfer heat by direct contact (conduction). Ocean water can absorb
and release energy by radiation as well. Some energy reflects off water at certain angles.
7. Small amounts of “greenhouse gases” like CO2 ________________.
a.
b.
c.
d.
e.
are able to block a large portion of in-coming solar energy
are able to absorb a significant portion of out-going long-wave radiation
are able to absorb most incoming solar energy
All of the above are true
None of the above are true
Carbon dioxide and other greenhouse gases are more adept at absorbing out-going long-wave radiation than
they are at blocking incoming short wave length solar energy.
8. Most in-coming solar energy is relatively high-temperature long-wave radiation. Out-going radiation
is cooler because of energy loss to oceans and land, and is shorter wave length so that it can escape
Earth’s atmosphere.
True ___
False ___
In-coming solar energy is mostly short wave and is not “thermal” or heat until it is absorbed and converts to
longer-wave and/or infrared thermal energy that we describe as ‘heat’.
9. Which type of severe thunderstorms spawn the most tornadoes?
a.
b.
c.
d.
e.
Supercells
Air mass thunderstorms
Squall lines
Mesoscale convective systems
Derechos
The latest edition of the textbook says that supercells spawn the most severe tornadoes. It is still possible that
most tornadoes develop from MCS or in other ways. Answers ‘a’ and ‘d’ should be considered correct.
10. If polar ice caps continue to melt, Earth’s overall albedo will probably rise.
True ___
False ___
As water goes from ice and snow to dark liquid, reflection (albedo) should be lower.
11. Atmospheric nitrogen comprises about 78% of Earth’s atmosphere and is a powerful greenhouse gas.
True ___
False ___
Nitrogen is not a greenhouse gas. Nitrogen also plays little or no role in blocking in-coming solar radiation..
12. Humidity is the result of condensation when clouds form. .
True ___
False ___
Humidity is lost as condensation occurs. Evaporation creates humidity and condensation releases humidity
back to liquid.
13. Violent storms erupt when cool, dry air rises quickly, releasing latent heat that was stored previously
in the atmosphere during condensation.
True ___
False ___
Cool, dry air does not rise easily, and contains relatively little latent heat. Condensation does not store latent
heat as humidity; condensation releases latent heat when vapor saturation occurs.
14. The troposphere is the lowest portion of Earth’s atmosphere. Because it is adjacent to dry land and
oceans, turbulence and mixing occur. The world’s storms occur in the troposphere.
True ___
False ___
Everything in Question 14 is true.
15. Average atmospheric pressure is about 7.3 pounds per square inch at 18,000 feet above sea level.
That same pressure also measures about 507 mb.
True ___
False ____
The density of Earth atmosphere drops by half from sea level to about 18,000 feet. Measured in millibars, sea
level air pressure should be about 1,013mb and half that at 18,000 feet.
16. There is a negative correlation between Earth’s overall albedo and overall average atmospheric
temperature.
True ___
False ___
Warmer air melts more ice. Less ice means less reflection or albedo. So, more heat = less albedo over time.
17. Based on class discussion, if very dry air is 100º F at sea level then what temperature should very dry
air be at 10,000 feet directly above that same location?
a.
b.
c.
d.
120º F.
150º F
50º F
0º F
e. None of the above is a good estimate
Ten thousands of altitude at 5 degrees each = 50 degree change in temperature so 100 – 50 = 50 degrees at
10,000 feet higher.
18. Blizzards contain vast amounts of atmospheric heat.
True ___
False ___
Even the coldest blizzard contains air and ice that are still hundreds of degrees warmer than absolute zero.
19. Which of the following statements is true regarding normal weather and stormy weather?
a.
b.
c.
d.
e.
A hurricane will occur if air pressure rises 50-100 mb.
A vertical change in air pressure of about 1,000 mb is possible during severe weather.
Horizontal changes in air pressure are relatively unimportant in storm development.
Air pressure drops rapidly with altitude during normal weather and during storms.
All of the above are true.
Storms exhibit lower air pressure between horizontal locations or at any given location over time. A pressure
drop of 50mb at any location or between two surface locations is sufficient for a strong storm. Vertical
differences in air pressure are huge over just a few thousand feet, and that is normal every day.
20. Evaporation is the process of converting sensible heat we can feel to latent heat we cannot feel.
Evaporation stores a vast amount of energy in latent form that will cause rapidly rising air when
condensation occurs and clouds form. Very tall clouds mean windy conditions.
True ___
False ___
All true.
21. A dust devil and a tornado are both provoked by hot air near the surface. Dust devils lack latent heat
in humidity, so they tend to be much weaker than tornadoes.
True ___
False ___
All true.
22. Swamp coolers (evaporative coolers) are very similar to Earth’s atmosphere because __________.
a.
b.
c.
d.
e.
they are both good at turning hot air into dry air that is free of latent heat
they both condense heat into liquid water that drains into a pipe, making people feel cooler
they both work like a hair dryer, turning liquid water into invisible vapor
All of the above are true
None of the above are true
Hair dryers and Earth’s atmosphere both evaporate liquid water into humidity that contains latent heat.
Evaporation uses heat to change the chemical structure of water. Energy that is ‘consumed’ in breaking water
bonds of cohesion is not lost; it remains latent in that chemical structure in the form of vibrating molecules.
23. The United States hosts most of the world’s tornadoes because there is no other place on Earth where
cooler, drier air from the west collides more directly with warm, wet air from the Atlantic Ocean
and/or Gulf of Mexico.
True ___
False ___
All true.
24. Air mass thunderstorms can occur almost anywhere warm, humid air is available. Typically, an air
mass thunderstorm ____________________.
a.
b.
c.
d.
e.
lasts for at least 10 hours, with cloud tops reaching at least 55,000 feet
lasts for about 30 minutes, with clouds no higher than about 25,000 feet
will include several meso-scale convective systems or even a ‘supercell’ embedded inside
might include a brief microburst downdraft that could interfere with airplanes in flight
Answers ‘b’ and ‘d’ are associated with simple air mass thunderstorms.
Simple air mass thunderstorms last less than an hour and do not reach anywhere near the tropopause. Larger
storms, including MCS and supercells can produce towering cumulonimbus clouds that can reach 50,000 feet or
more and can last for hours. Larger, stronger storms are more likely to also produce hazardous micro-burst
downdrafts.
25. For Utah to have more severe storms and more tornadoes we need ______________.
a.
b.
c.
d.
e.
more heat
more water
fewer mountains
higher air pressure
All of the above.
Utah has plenty of heat. We just lack water that can hold even more heat in latency, where it can return when
humidity condenses back to liquid, adding energy to storm activity.
26. Doppler radar is a modern invention that allows weather forecasters to detect wind direction and
speed by counting molecules of nitrogen and oxygen as they pass through a grid or screen. Raindrops
are too small for detection by Doppler radar.
True ___
False ___
Doppler radar cannot count or detect atmospheric gas molecules; instead, it detects more solid things like dust
and liquid water that are blown by wind. Raindrops are the most important target of Doppler radar detection.
27. Coriolis force is very weak near the Equator, which helps ensure that tornadoes and hurricanes
virtually never occur there.
True ___
False ___
All true.
28. .The ‘Enhanced Fujita’ scale ranks tornado intensity by wind speed, but uses tornado damage to
determine intensity. That dual system can be confusing, but reflects the fact that measuring actual
tornado wind speed is almost impossible. So, we use actual damage as a substitute for knowing actual
wind speed.
a. I agree with the statement above.
b. The EF scale is based on a concept that is similar to the Modified Mercalli system for estimating
earthquake intensity.
c. Answers ‘a’ and ‘b’ above are both valid.
d. None of the above answers are valid.
Answers ‘a’ and ‘b’ are both valid.
29. Coriolis force is strong in the mid-latitudes of the northern hemisphere, which causes artillery shells,
missiles and baseballs in flight to deflect to the right. As a result, mid-latitude cyclones tend to be
more hazardous than storms near the Equator.
True ___
False ___
All true.
30. Recent research using high-speed photography has proven that lightning bolts actually rise from the
ground. Energy stored in rocks and dirt discharge from ground to clouds, rather than from clouds to
ground.
True ___
False ___
Energy for lightning is generated in the sky and is released from the sky to the ground.
31. Mid-latitude cyclones are storms that include _______________.
a.
b.
c.
d.
e.
high pressure rising air that rotates counter-clockwise while releasing latent heat
low-pressure sinking air that releases rain and snows as it descends
high-pressure sinking air that rotates clockwise, releasing rain and/or snow
low-pressure rising air that rotates counter-clockwise while releasing latent heat and moisture
All of the above are correct.
Cyclones in the northern hemisphere are always about rising air that rotates counter-clockwise because of
Coriolis effect and pressure gradient.
32. Catastrophic “Super-Storm Sandy” resulted from collision between a weakened hurricane and a
“nor-easter” storm that contained colder air. The nor’easter storm did not add energy to the
hurricane but encouraged more vigorous lifting of humid air that was still available the ex-hurricane.
Many people were killed by the extra energy found in a storm that had been fading.
True ___
False ___
The last statement is false and is contradictory to everything else in Question 32. More energy was not added
by the Nor’easter storm. Instead, the cold Nor’easter just helped extra more energy of what remained .
33. Warm, wet air is the primary component of storms that deliver precipitation. Cool, dry air is an
important component in mid-latitude cyclones, by making it easier for humid air to rise. A dry-line
storm is not dry at all, but is based on the difference in humidity between opposing air masses along a
weather front or line.
True ___
False ___
All statements in Question 33 are true, and helpful.
34. A hazardous micro-burst can occur when air inside a thunderstorm suddenly accelerates upward
instead of sinking.
True ___
False ___
Micro bursts are vigorous downdrafts that occur after warm, humid rising air has becoming drier and more
dense. Intense rainfall can also can help “pull” air down. Dry, cool air does not tend to rise.
35. Which of the following processes does not affect the growth of fair-weather cumulus clouds into
towering cumulo-nimbus thunderstorms?
a. Enough heat and humidity are available to sustain re-heating by condensation far into the
troposphere.
b. At 30,000 feet or higher, air pressure is very low, causing rising air to cool by decompression
and release additional heat for more lifting.
c. Colder air aloft can promote faster rising storm air by making it easier for latent heat to be
released during condensation.
d. The presence of cooler, drier air nearby will tend to quickly shut off storm development.
e. Nightfall and loss of solar heating do not automatically stop storm development, and tornadoes
often occur at night.
Answer ‘d’ is not consistent with the other options. For instance, option is good: a hot air balloon will rise
faster if air nearby is colder.
36. Improved weather forecasting has now reduced the typical amount of tornado warning time from 11
or 12 minutes to less than two or three minutes.
True ___
False ___
The opposite is true. Average warning times have increased to about 12 minutes.
37. According to news reports discussed in class, recent research is suggesting that public shelters no
longer be provided for safety against tornadoes in the United States.
True ___
False ___
People may expose themselves to unnecessary hazard by traveling to a shelter, so it might be safer to just stay
where you are. Also, there is not enough money to build shelters large enough to hold everyone, so people
should be encouraged to build their own shelters and stay there.
38. Tornado season in the United States begins in late summer when enough atmospheric heat has
accumulated to produce hot, humid weather. All cold air and snow pack are finally gone.
True ___
False ___
Tornado season in the United States begins in Spring when there is still plenty of cold air available to help
warm, humid air rise even faster, creating faster surface winds. By late summer, tornadoes are less common
because there is less contrast between air masses across the U.S. Midwest.
39. Dangerous “derecho” winds are generally high-speed straight-line winds that run for hundreds of
miles. Derecho winds are thunderstorm-related but may occur where it is not raining.
True ___
False ___
All true.
40. In Utah, hailstones, rain and even snow can evaporate to nothing before reaching the ground. This
phenomenon is known as virga and can cause micro-bursts because evaporation causes air to cool and
sink rapidly.
True ___
All true.
False ___