15-3
Layers of the Atmosphere
1. Identify the four main layers
of the atmosphere.
2. Describe the characteristics
of each layer.
1. Identify the four main
layers of the atmosphere.
Key Concept: Scientists divide
Earth’s atmosphere into four
main layers classified
according to changes in
temperature.
These layers are the troposphere,
the stratosphere, the
mesosphere, and the
thermosphere.
Scientists divide the
atmosphere into four layers.
They classify these layers by
the changes in temperature. As
you go from one layer to the
next, the temperature changes
in a different way.
Layers vs.
Temperature
Answer the following questions. Use your textbook and the
ideas above.
1. In the picture below, fill in the blanks.
120
Thermosphere
100
80
mesosphere
60
b.
40
Strastosphere
Stratospher
e
20
0
a.
troposphere
1. Is the following sentence true or false? Scientists divide
the atmosphere into layers based on thickness.
False
2. Describe the
characteristics of each layer.
The Troposphere (page 524)
Key Concept: The troposphere is
the layer of the atmosphere in
which Earth’s weather occurs.
You live in the troposphere
(TROH puh sfeer). It is the
lowest layer of the atmosphere.
Most weather happens in the
troposphere. For example, when
it is raining, it is raining in the
troposphere.
The troposphere contains
almost all of the mass of the
atmosphere.
In the troposphere, the
temperature decreases as the
altitude increases. In other
words, the higher you go in the
troposphere, the colder it gets.
Answer the following questions. Use your textbook and the
ideas above.
1. Circle the letter of each sentence that is true about the
troposphere.
a. The troposphere is the lowest layer of the
atmosphere.
b. Most weather happens in the troposphere.
c. The troposphere contains almost no mass.
2. Is the following sentence true or false? In the
troposphere, the temperature increases as the altitude
increases.
False
The Stratosphere (page 525)
Key Concept: The stratosphere is
the second layer of the
atmosphere and contains the
ozone layer.
The stratosphere is the layer of
the atmosphere just above the
troposphere. It is just below the
mesosphere.
The middle portion of the
stratosphere contains the ozone
layer.
The ozone layer is where there
is more ozone than in any other
part of the atmosphere. The
ozone layer blocks harmful
energy from the sun.
In the stratosphere, the
temperature increases as the
altitude increases. In other
words, the higher you go in the
stratosphere, the warmer it
gets.
ideas above.
1. The layer just above the troposphere is the
.
stratosphere
2. Circle the letter of each sentence that is true about the
stratosphere.
a. The stratosphere is just below the thermosphere.
b. The middle portion of the stratosphere contains the
ozone layer.
c. The higher you go in the stratosphere, the warmer
it gets.
3. Is the following sentence true or false? In the
stratosphere, the temperature decreases as the
altitude increases.
false
The Mesosphere (page 526)
Key Concept: The mesosphere is
the layer of the atmosphere that
protects Earth’s surface from
being hit by most meteoroids.
The mesosphere is the layer of
the atmosphere just above the
stratosphere.
In the
mesosphere,
the temperature
decreases as
the altitude
increases. So,
the higher you
go in the
mesosphere,
the colder it
gets.
A meteoroid is a chunk of rock or
metal from space. Most
meteoroids heading toward Earth
burn up in the mesosphere.
Answer the following questions. Use your textbook and the
ideas above.
1. Circle the letter of each sentence that is true about the
mesosphere.
a. Most meteoroids heading toward Earth burn up in
the mesosphere.
b. In the mesosphere, the temperature decreases as
the altitude increases.
c. The mesosphere is the layer just above the
thermosphere.
2. A chunk of rock or metal from space is a(n)
meteoroid
.
The Thermosphere
(pages 526–527)
Key Concept: The outermost
layer of Earth’s atmosphere is
the thermosphere.
The top layer of the atmosphere
is the thermosphere. It is above
the mesosphere.
In the thermosphere, the
temperature increases as the
altitude increases. So, the higher
you go in the thermosphere, the
higher the temperature is.
The thermosphere is divided
into two layers. The lower layer
of the thermosphere is called
the ionosphere
The colorful displays called the
Northern Lights take place in
the ionosphere.
The outer layer of the
thermosphere is called the
exosphere. The exosphere
gradually blends with outer
space.
ideas on page 247 and above.
1. Circle the letter of each sentence that is true about the
thermosphere.
a. The thermosphere is divided into two layers.
b. In the thermosphere, the temperature increases as
the altitude increases.
c. The thermosphere is the top layer of the
atmosphere.
2. Read each word in the box. In each sentence below,
fill in one of the words.
exosphere
mesosphere
ionosphere
a. The Northern Lights take place in the
b.
ionosphere
The exosphere
space.
.
gradually blends with outer
The End