Graphing the Atmosphere
MATERIALS
Reading handout, graph paper, pencil, colored pencils, ruler
PROCEDURE
 STEP 1: Assemble your graph and glue into your
notebook.
A. Cut off the extra paper on the top half of the second page of the graph. Glue the two pieces of paper together so the gridlines match. There will be
a little bit of overlap between 300 and 310.
B. The graph will be longer than the notebook and
can be folded up to fit. Fold the graph “in” at 390
and fold “back” at 180.
C. Cut off the extra paper on the right side so the
graph will fit in your notebook. Glue the back of
the top page into your notebook.
 STEP 2: Read the background information about
the atmosphere. Underline or highlight key words for
easy reference later on.
 STEP 3: Label the vertical and horizontal axes on
the graph. One should be labeled Average Temperature (°C) and the other should be labeled Altitude
(km). Use the data to help you figure out which one is
which.
 STEP 4: The data table contains the average temperature reading at different altitudes in the Earth’s
atmosphere. Plot this data on the graph and connect
each of the points as you plot them. Use a ruler to
draw lines. Be careful to plot the negative temperatures correctly.
Average Temperatures in
Earth’s Atmosphere
Average
Temperature (°C)
Altitude (km)
15
0
-18
5
-49
10
-56
12
-56
20
-51
25
-46
30
-37
35
-22
40
-8
45
-2
48
-2
52
-7
55
-17
60
-33
65
-54
70
-65
75
-79
80
-86
84
-86
92
-81
95
-72
100
-30
500
-72
600
 STEP 5: Color code and label the five layers of the
atmosphere in the bar to the right of your graph.
Write the entire word to label each layer.
 Troposphere = RED
 Stratosphere = YELLOW
 Mesosphere = GREEN
 Thermosphere = BLUE
 Exosphere = PURPLE
 STEP 6: Draw and label the four boundaries between layers of the atmosphere.
 Draw a horizontal line across the graph at each of
the following altitudes: 15 km, 50 km, 90 km, 500
km.
 Label the four boundaries of the layers on the
graph (write the entire word):
 Tropopause
 Stratopause
 Mesopause
 Thermopause
 STEP 7: Find the location of the ozone layer.
 Shade the location of the ozone layer across the
graph in ORANGE colored pencil.
 Label the ozone layer.
 STEP 8: Use your graph and the background information to complete the “Analyze and Conclude”
questions.
THE ATMOSPHERE
The atmosphere can be divided into five layers based on temperature
differences. The layer closest to Earth is called the troposphere. Above this layer
is the stratosphere, followed by the mesosphere, then the thermosphere, and
finally the exosphere. The temperature differences in the layers are caused by the
way solar energy is absorbed as it moves down through the atmosphere.
Troposphere
The Earth’s surface absorbs most of the solar energy. Some of the energy radiates
off the surface as heat, which warms the troposphere. The average temperature
of the troposphere decreases as the altitude increases. In other words, the higher
up the air is, the colder it gets. The global average temperature on the
troposphere rapidly decreases with altitude until the tropopause, which is the
boundary between the troposphere and the stratosphere.
Glue this side down
Stratosphere
The temperature begins to increase with altitude in the stratosphere. This
warming is caused by ozone (O3), a form of oxygen which absorbs ultraviolet (UV)
radiation from the sun. Ozone is a dangerous pollutant when it is found in the
troposphere, but the ozone layer in the stratosphere, located approximately 20 to
30 kilometers above the surface of the Earth, protects us from the suns UV
radiation. UV rays can cause sunburn, cancer, and genetic mutation. At the
stratopause, the boundary between the stratosphere and the mesosphere, the
temperature stops increasing with altitude.
Mesosphere
Weather balloons can only travel into the stratosphere below, and satellites orbit
in the thermosphere above, so scientists have not been able to gather much
information about the mesosphere. We do know that the air in the mesosphere is
very thin so it does not absorb radiated heat from the sun, which makes the
temperature decrease with altitude. It continues to decrease until the
mesopause, which is the upper boundary of the mesosphere.
Thermosphere and Exosphere
At the mesopause, the temperature begins to increase again and this continues
through the thermosphere, the warmest layer of the atmosphere. This layer is
where solar radiation first hits the atmosphere and heats it. The air in the
thermosphere is so thin, a thermometer cannot measure the temperature
accurately and special instruments are needed. Even though it is very hot in the
thermosphere, the molecules are so spread out, that it does not feel warm, so the
International Space Station and other satellites can orbit safely through this layer
of the atmosphere. The upper boundary of the thermosphere is the thermopause,
after which comes the final layer of the atmosphere, the exosphere, which is
where space begins.