Transcript Section 5 PowerPoint

Chapter Resources Menu
Study Guide
Section 13.1
Section 13.2
Section 13.3
Section 13.4
Chapter Assessment
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Section 13.1 Study Guide
Section 13.1 Main Ideas
• For a thunderstorm to occur, there must be abundant
moisture in the lower levels of the atmosphere and a
mechanism to lift the moisture so it can condense. In
addition, the air must be unstable so that the growing
cloud will continue to rise.
• Thunderstorms are classified according to the
mechanism that caused the air to rise. In an air-mass
thunderstorm, the cloud rose because of unequal
heating of Earth’s surface within one air mass. In a
frontal thunderstorm, the air rose because it was pushed
up by an advancing air mass.
Section 13.2 Study Guide
Section 13.2 Main Ideas
• Lightning is produced when an advancing stepped leader
unites with an upward-moving return stroke. Thunder is
the sound made by the rapid expansion of air around the
lightning bolt as a result of extreme heating of the
lightning channel.
• Thunderstorms can damage property and cause loss
of life. The hazards of thunderstorms include lightning,
violent winds, hail, floods, and tornadoes.
• The Fujita tornado intensity scale classifies tornadoes
according to wind speed, path of destruction, and
duration.
Section 13.3 Study Guide
Section 13.3 Main Ideas
• Tropical cyclones derive their energy from the evaporation
of warm ocean water and the release of heat.
• The Saffir-Simpson hurricane scale classifies hurricanes
according to intensity.
• Hurricane hazards include violent winds, floods, and
storm surges. The National Hurricane Center tracks
hurricanes and issues advance warnings to help reduce
loss of life.
Section 13.4 Study Guide
Section 13.4 Main Ideas
• Examples of persistent weather events include floods,
droughts, cold waves, and heat waves.
• The heat index assesses the impact of humidity
combined with excessive heat on the human body. The
wind-chill index estimates the heat loss from human skin
caused by a combination of cold air and wind.
Chapter Assessment
Multiple Choice
1. Which of the following states experiences the
highest number of thunderstorm days annually?
a. Oklahoma
c. Florida
b. Tennessee
d. Iowa
Almost the entire state of Florida experiences more than
70 thunderstorm days annually.
Chapter Assessment
Multiple Choice
2. The ____ causes the illumination that
you see as lightning.
a. stepped leader
c. channel
b. return stroke
d. thunder
The stepped leader is the invisible channel of
negatively charged air that moves from the cloud
toward the ground. The return stroke rushes upward
from the ground to meet it, illuminating the channel
with about 100 million V of electricity.
Chapter Assessment
Multiple Choice
3. Which classification on the Fujita tornado
intensity scale represents a strong tornado?
a. F0
c. F3
b. F1
d. F5
F0 and F1 are classified as weak tornadoes. F2 and F3
are classified as strong tornadoes. F4 and F5 are
classified as violent tornadoes.
Chapter Assessment
Multiple Choice
4. Which of the following areas is least likely to be
hit by a hurricane or typhoon?
a. western Africa
b. eastern United States
c. southern Japan
d. eastern India
As a general rule, the most likely areas to be hit by a
hurricane are on the eastern side of continents.
Australia is the exception; both its east and west
coasts are vulnerable.
Chapter Assessment
Multiple Choice
5. Cold waves are caused by ____.
a. high-pressure systems
b. low-pressure systems
c. mT air masses
d. cT air masses
Cold waves are brought on by large high-pressure
systems that originate in the polar regions.
Chapter Assessment
Short Answer
6. Explain why cold-front thunderstorms can last
through the night?
Cold-front thunderstorms get their initial lift from
the push of cold air. They are not dependent on
daytime heating. The thunderstorm can persist
as long as the flow of moist, warm air into it is
not disrupted.
Chapter Assessment
Short Answer
7. What is wind shear and why is it important in the
formation of tornadoes?
Wind shear is when wind speed and direction
change suddenly with height. This can produce
a horizontal rotation near Earth’s surface. If this
occurs close to the thunderstorm’s updrafts the
twisting column of wind can be tilted from a
horizontal to vertical position.
Chapter Assessment
True or False
8. Identify whether the following statements are
true or false.
______
true Tornadoes can occur virtually anywhere
on Earth.
______
false Typical thunderstorms last about two hours.
______
true High instability in the atmosphere limits
thunderstorms.
______
true Air-mass thunderstorms generally occur during
mid-afternoon.
______
false Tropical disturbances have a cyclonic
circulation.
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Chapter 13 Images
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Chapter 13 Images
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Chapter 13 Images
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