How can knowing about jet streams help a pilot?
Jet streams are fast flowing, narrow air currents found in the upper atmosphere or in troposphere of some planets, including Earth.[1] The main jet streams are located near the altitude of the tropopause. The major jet streams on Earth are westerly winds (flowing west to east). Their paths typically have a meandering shape; jet streams may start, stop, split into two or more parts, combine into one stream, or flow in various directions including the opposite direction of most of the jet. The strongest jet streams are the polar jets, at around 9–12 km (30,000–39,000 ft) above sea level, and the higher and somewhat weaker subtropical jets at around 10–16 km (33,000–52,000 ft). The Northern Hemisphere and the Southern Hemisphere each have a polar jet and a subtropical jet. The northern hemisphere polar jet flows over the middle to northern latitudes of North America, Europe, and Asia and their intervening oceans, while the southern hemisphere polar jet mostly circles Antarctica all year round.
Jet streams are caused by a combination of a planet's rotation on its axis and atmospheric heating (by solar radiation and, on some planets other than Earth, internal heat). Jet streams form near boundaries of adjacent air masses with significant differences in temperature, such as the polar region and the warmer air towards the equator.[2]
Other jet streams also exist. During the Northern Hemisphere summer, easterly jets can form in tropical regions, typically in a region where dry air encounters more humid air at high altitudes. Low-level jets also are typical of various regions such as the central United States.
Meteorologists use the location of some of the jet streams as an aid in weather forecasting. The main commercial relevance of the jet streams is in air travel, as flight time can be dramatically affected by either flying with the flow or against the flow of a jet stream. Clear-air turbulence, a potential hazard to aircraft passenger safety, is often found in a jet stream's vicinity, but it does not create a substantial alteration on flight times.[citation needed]
more info: https://en.wikipedia.org
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Name_________________________________________________Period___________
CHAPTER 15 DIRECTED READING
The Atmosphere
Section 1: Characteristics of the Atmosphere (p. 392)
1. Why is the atmosphere important to us? (Circle all that
apply.)
a. It contains the oxygen we breathe.
b. It keeps the clouds close to the Earth.
c. It protects us from the sun’s harmful rays.
d. It holds us onto the Earth’s surface.
Mark each of the following statements True or False.
2. The atmosphere contains some solids. True or False.
3. Oxygen is the most abundant gas in Earth’s atmosphere True or False.
4. Water is the most abundant liquid in Earth’s atmosphere. True or False.
(p. 393) Atmospheric Pressure and Temperature
5. Why do your ears pop when you ride up or down in an
elevator in a tall building?
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6. Gravity holds the atmosphere around the Earth. True or False? (Circle one.)
7. Air pressure___(increases or decreases)____ as you
move away from Earth’s surface.
8. Differences in temperature between layers of the
atmosphere are mainly due to the way_____________________ is absorbed by gases
as it moves downward through the atmosphere.
(p. 394) Layers of the Atmosphere
9. In which of the following atmospheric layers does
temperature decrease as altitude increases? (Circle all that apply.)
a. troposphere c. mesosphere
b. stratosphere d. thermosphere
10. The pressure of the Earth’s atmosphere becomes ____(greater
or lesser)__as you move away from the Earth’s surface.
11. Most of the mass of the Earth’s atmosphere is in the (troposphere
or thermosphere)
12. You live in the troposphere. True or False? (Circle
one.)
13. Take a look at Figure 5 at the bottom of page 395. Ozone
is made up of oxygen atoms. How is ozone different from the oxygen you breathe?
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14. The ozone in the atmosphere absorbs. (ultraviolet radiation
or gamma rays)
15. The coldest layer of the atmosphere is the
a. troposphere. c. mesosphere.
b. stratosphere. d. thermosphere.
16. The thermosphere isn’t a hot place, even though it has
very high temperatures. Why?
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17. Ions are electrically charged particles. True or False? (Circle one.)
18. Ions in the thermosphere are created when
a. the aurora borealis hits nitrogen atoms.
b. AM radio waves are absorbed by oxygen atoms.
c. nitrogen and oxygen atoms absorb solar energy.
d. meteorites pass through nitrogen and oxygen atoms.
19. There is a definite boundary between the atmosphere and
space, called the ionosphere. True or False? (Circle one.)
(p. 397) Review: Now
that you’ve finished Section 1, review what you learned by answering the Review
questions in the back of your notebook
Section 2: Heating of the Atmosphere (p.
398)
1. The
Earth’s atmosphere is heated by solar energy. True or False? (Circle one.)
Energy in the Atmosphere (p. 398)
2. The Earth receives about_______________________of the radiation
released by the sun.
3. Take a moment to look at Figure 8. What percentage of the
sun’s radiation that reaches the Earth is absorbed or reflected in each of the
following ways?
__________________scattered and reflected by clouds and air
__________________reflected by the Earth’s surface
__________________absorbed by the Earth’s surface
__________________absorbed by ozone, clouds, and atmospheric
gases
4. Energy transferred by heat from the sidewalk to your foot
is an example of _________.
(conduction or convection)
5. In convection currents, cold air (sinks or rises).
(p. 400) The Greenhouse Effect
6. Gases in the atmosphere can gain energy from the land and
water. True or False?
7. Take a look at Figure 10. How do greenhouse gases act
like the layer of glass in a greenhouse?
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Mark each of the following statements True or False.
8. An increase in carbon dioxide might cause global warming
because more carbon dioxide would be able to trap more heat. True
or False
9. The balance between incoming radiation and out-going heat
is called the radiation balance. True or
False
10. Rising temperatures on Earth would not cause major
changes in plant and animal communities. True
or False
11. Why would planting millions of trees help reduce the
green- house effect?
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Review (p. 401)
Now that you’ve finished Section 2, review what you learned by answering the
Review questions in the back of your notebook.
Section 3: Atmospheric Pressure and Winds (p. 402)
1. The damage in Figure 12 was caused by moving air. True or False? (Circle one.)
(p. 402) Why Air Moves
2. Differences in air pressure create wind. True or False? (Circle one.)
3. The greater the difference is between areas of high and
low pressure, the faster the wind speed. True
or False? (Circle one.)
4. ________________air has a higher density than __________________air.
5. Air pressure is high at the__________________ because the
air is___________ there.
(poles or equator,
hot or cold)
6. What produces pressure belts?
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7. The winds in the Southern Hemisphere curve to the right
due to the Coriolis effect. True or
False? (Circle one.)
8. In Figure 15 at the bottom of page 403, what happens if
you try to roll a marble across a spinning Lazy Susan?
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Types of Winds (p. 404)
9. Which of the following is NOT true of local winds?
a. They are caused by the uneven heating of the Earth’s
surface and pressure differences.
b. They can blow from any direction.
c. They usually move short distances.
d. They are part of a pattern of air circulation that moves
across the Earth.
Complete the
following questions after reading pages 404–406. Be sure to review the
figures on those pages.
10. The word doldrums comes from an Old English word that
means
“foolish.” Why were the doldrums given that name?
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11. The areas of high pressure at 30 north and 30 south
latitude are called the____________________________.
12. In the Southern Hemisphere, the westerlies blow from the
southeast to the northwest. True or
False? (Circle one.)
13. The polar easterlies in the Northern Hemisphere blow
from the _____________to the _____________.
14. How can knowing about jet streams help a pilot?
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Choose the global winds in Column B that best match the
description in Column A, and write the corresponding letter in the space
provided.
Column
A
|
Column
B
|
_______15. winds that blow toward the poles between 30 and
60 latitude in both hemispheres
|
a. polar easterlies
|
_______16. narrow belts of high-speed, high-altitude winds
that do not follow regular paths
|
b. westerlies
|
_______17. winds moving from the poles toward 60
latitude in both hemispheres
|
c. northeast trade winds
|
_______18. winds that move from northeast to southwest toward
the equator
|
d. jet streams
|
Look at Figure 19 on
page 406, and then answer the following
questions about sea
breezes and land breezes.
19. In the afternoon on the beach, after the sun has heated
the land, you can feel___________ breezes. (sea or land)
20. Sea breezes and land breezes are created because air
moves from areas of high pressure to areas of low pressure. True or False? (Circle one.)
Look at Figure 20 on
page 407, and then answer the following questions about mountain and valley
breezes.
21. In the afternoon in the mountains, after the sun has
heated the valley floor all day, you can feel a __________________ breeze.
(mountain or valley)
(p. 407) Review: Now
that you’ve finished Section 3, review what you learned by answering the Review
questions in the back of your notebook
Section 4: The Air We Breathe (p. 408)
1. Air pollution in cities only became a problem in the
twentieth century. (True or False)?
(p. 408) Air Quality
2. Which of the following are natural air pollutants? (Circle
all that apply.)
a. sea salt d. vehicle exhaust fumes
b. swamp gas e. pollen
c. smoke from forest fires f. volcanic gases
(p. 409) Types of Air Pollution
3. All primary pollutants are put into the air by humans. True or False? (Circle one.)
4. Ozone and smog
a. are made up of automobile exhaust.
b. are primary pollutants.
c. are formed when automobile exhaust reacts with sunlight.
d. are formed when automobile exhaust reacts with water.
Sources of Human-Caused Air Pollution (p. 410)
5. The main source of human-caused air pollution today is .
(transportation or industry)
6. The burning of fossil fuels releases large amounts of
oxides into the air. True or False?
(Circle one.)
7. List three things that contribute to indoor air pollution.
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The Air Pollution Problem (p. 411)
Mark each of the following statements True or False.
8. Pollution always stays in the area where it is released. True or False
9. Acid precipitation can kill trees and fish. True or False
10. The ozone hole is dangerous because it allows more UV
radiation to reach the Earth. True or
False
11. Which of the following are possible effects of air
pollution on the human body? (Circle all that apply.)
a. lung cancer
c. coughing
b. burning eyes d. runny nose
(p. 412) Cleaning Up Our Act
12. The EPA can control the amount of air pollutants that
can be released from any human-controlled source. True or
False? (Circle one.)
13. The EPA has set a standard for the amount of ___________________that
comes out of the _____________________on new cars.
14. How many tons of ash do scrubbers remove each year from
the
smokestacks of coal-burning plants?
________________________________
Review (p. 413) Now
that you’ve finished Section 4, review what you learned by answering the Review
questions in the back of your notebook.
