Transcript UNIT THREE: Matter, Energy, and Earth  Chapter 8 Matter and Temperature  Chapter 9 Heat  Chapter 10 Properties of Matter  Chapter 11

UNIT THREE: Matter, Energy, and
Earth
 Chapter 8 Matter and Temperature
 Chapter 9 Heat
 Chapter 10 Properties of Matter
 Chapter 11 Earth’s Atmosphere and
Weather
Chapter Eleven: Earth’s Atmosphere
and Weather
 11.1 Earth’s Atmosphere
 11.2 Weather Variables
 11.3 Weather Patterns
Investigation 11A
Heating Land and Water
 Key Question:
How does solar radiation affect the heating and
cooling of continents and oceans?
11.1 Learning Goals
 Describe the composition of Earth’s
atmosphere.
 Explain the meaning of atmospheric pressure
and describe how it is measured.
 Identify the layers of Earth’s atmosphere and
discuss unique characteristics of each layer.
11.1 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.
11.1 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.
 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.
11.1 Nitrogen Cycle
 Nitrogen is important
to protein which is
found in the body
tissues of all living
things.
 Nitrogen is cycled
through the soil and
into plants and finally
when living things die
and decay.
11.1 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.
Photosynthesis changed Earth’s atmosphere.
Photosynthesis and the atmosphere
 Photosynthesis
converts carbon
dioxide to oxygen in
a process that
allows living things
use the sun’s
energy.
11.1 Earth stores carbon
 Many marine
organisms such as
microscopic
phytoplankton use
carbon dioxide
dissolved in
seawater to form
shells of calcium
carbonate.
11.1 Atmospheric
pressure
 Atmospheric pressure is
a measurement of the
force due to air molecules
at a given altitude.
 The pressure of the
atmosphere decreases as
you rise above sea level.
11.1 Pressure changes with altitude
11.1 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?
11.1 Measuring Pressure
11.1 Measuring Pressure
 A barometer is an
instrument that
measures
atmospheric pressure.
 Long ago, mercury
barometers were
used.
11.1 Parts of an Aneroid Barometer
11.1 Layers of the
Atmosphere
 Four Layers
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Thermosphere
Mesosphere
Stratosphere
Troposphere*
11.1 Our Atmosphere
1. Troposphere: where
we live
2. Stratosphere:
contains the ozone
layer
3. Mesosphere: where
the temperature is
coldest
4. Thermosphere, where
the temperature is
highest
Other layers
 The ionosphere is part of
the thermosphere and is
where the Sun’s
ultraviolet light creates
charged atoms and
molecules called ions.
 The exosphere begins at
about 500 kilometers
above Earth’s surface and
does not have a specific
outer limit.