Integrated Science
Unit 9, Chapter 26
Unit Nine: Energy in the Earth System
Chapter 26 Energy in the Atmosphere
26.1
The Atmosphere
26.2
Layers of the Atmosphere
26.3
Energy in the Atmosphere
Chapter 26 Learning Goals
Learn about the thermal structure and chemical composition of Earth’s
atmosphere.
 Compare and contrast the atmospheres of Venus, Earth, and Mars.
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Find out how life on Earth has changed Earth’s atmosphere.
Build and calibrate a barometer to measure atmospheric pressure.
Learn how changing atmospheric pressure affects the weather.
Describe the layers and the corresponding temperature changes in the
atmosphere.
Learn about ozone’s helpful role in the stratosphere and harmful role in
the troposphere.
Measure ozone levels in your school.
Describe energy transfer in the atmosphere.
Discuss greenhouse gas emission reduction and other means of slowing
global warming.
 Model factors affecting Earth’s temperature, including greenhouse gases,
thermal buffering properties of ice, and water’s high specific heat.
Chapter 26 Vocabulary Terms
 atmosphere
 atmospheric
 ionosphere
pressure
 mesosphere
 barometer
 ozone
 chlorofluorocarbons
 stratosphere
 exosphere
 thermosphere
 greenhouse
 global
effect
warming
 troposphere
26.1 The Atmosphere

Earth’s atmosphere is a
layer of gases surrounding
the planet, protecting and
sustaining life.
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—
It insulates us so that we
don’t freeze at night.
Its ozone layer protects us
from the sun’s ultraviolet
rays.
It also contains the carbon
dioxide needed by plants for
photosynthesis, and the
oxygen we need to breathe.
26.1 What's in Earth's atmosphere?

This wonderful protective layer exists around Earth
because our planet has just the right balance of
size and distance from the sun.
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Nitrogen gas makes up about
78 percent of Earth’s
atmosphere.

The second most abundant
gas is oxygen, which makes
up 21 percent of Earth’s
atmosphere.
26.1 Nitrogen Cycle

Nitrogen is released into the air by
volcanoes and decaying organisms.
 Nitrogen is not absorbed directly
from the air. Instead, the nitrogen is
changed into nitrates (NO3) by
nitrogen-fixing organisms in the
soil.

Plants absorb nitrates from the soil
and use them to make proteins.
 We eat plants (especially their
seeds) or meat to obtain these
proteins.
26.1 Why is Earth different?
 The
atmospheres of Venus, Earth, and Mars were
formed in similar ways, so we might expect them to
contain similar elements.
 Through
photosynthesis, life on Earth has actually
changed the planet’s atmosphere.
26.1 Atmospheric pressure
 Atmospheric
pressure is
a measurement of the
force of air molecules in
the atmosphere at a given
altitude.
 The
pressure of the
atmosphere changes as
you rise above sea level.
26.1 Atmospheric pressure
 At
sea level, the weight of
the column of air above a
person is about 9,800
newtons (2,200 pounds)!
 This
is equal to the
weight of a small car.
 Why
aren’t we crushed by
this pressure?
26.1 Measuring Pressure
26.1 Pressure changes with altitude
26.1 The Atmosphere
Key Question:
Can you measure atmospheric pressure?
*Read text section 26.1 BEFORE Investigation 26.1
Parts of an Aneroid Barometer
26.2 Layers of the
Atmosphere
 Four
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—
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Layers
Thermosphere
Mesosphere
Stratosphere
Troposphere*
26.2 Layers of the
Atmosphere
 The
atmosphere is
divided into layers based
on temperature changes.
 We
live in the
troposphere which is 0 to
11 kilometers above
Earth's surface.
Layers of the
Atmosphere
The four layers of the atmosphere
include:
1.
the troposphere, where we
live;
2.
the stratosphere, which
contains the ozone layer;
3.
the mesosphere, where
meteors burn;
4.
and the thermosphere, where
satellites orbit Earth.
26.2 Layers of the Atmosphere
Key Question:
How much ozone is in our living areas?
*Read text section
26.2 BEFORE
Investigation 26.2
26.3 Energy in the Atmosphere

Our sun converts 5 million tons
of its own mass into energy
every second.
 This process involves nuclear
fusion.
 Even though Earth intercepts
only a tiny fraction of the
radiation broadcast by the sun
into space, this radiation
provides most of Earth’s
thermal energy.
26.3 Greenhouse effect

Imagine an empty bucket with a hole near the bottom.
 If you pour water into that bucket at the same rate
that the water spills out the hole, the bucket will never
get full.

If you fill the bucket partially with pebbles, it will take
longer for the water to get through the bucket and out
the hole.
26.3 Greenhouse effect

There are molecules in the atmosphere that act like
the pebbles in the bucket.

They make it take longer for the infrared radiation to
escape back into space.
26.3 Greenhouse effect
 Adding
greenhouse
gases to the atmosphere
is like adding more
pebbles to the bucket.
 It
takes longer for
radiation to escape from
the atmosphere, so
Earth’s average
temperature rises.
Gulf Stream and global warming
26.3 Energy in the Atmosphere
Key Question:
What factors affect Earth's temperature?
*Read text section 26.3 BEFORE Investigation 26.3