Transcript Chapter 15: Earth’s Atmosphere

Bellwork March 1, 2007
• Define the following words: Page 434
– Atmosphere
– Troposphere
– Ionosphere
– Ultraviolet Radiation (U.V. Radiation)
– Ozone Layer
– Chlorofluorocarbon (CFC’s)
Chapter 15:
Earth’s Atmosphere
What is the Atmosphere?
• The atmosphere surrounds Earth and protects
us by blocking out dangerous rays from the
sun.
• Is a mixture of gases that is layered and
becomes thinner until it gradually reaches
space.
• Insulates the Earth.
Composition of Earth’s
Atmosphere
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78% Nitrogen
21% Oxygen
~3% Water Vapor
0.93% Argon
0.04% Carbon Dioxide
trace amounts of other
gases
Layers of the
Atmosphere
• Divided into five
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different and distinct
layers.
Lower layers include
the troposphere and
stratosphere
Upper layers are the
mesosphere,
thermosphere and
exosphere.
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Lower Layers
• Troposphere
• Stratosphere
Troposphere
• Where we study, eat,
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sleep, and play.
Lowest of Earth’s
atmospheric layers.
Contains 99% of the
water vapor and 75% of
atmospheric gases.
Layer in which clouds
and weather occur.
Stratosphere
• ~ 10 km (6mi) to 50 km
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(30mi) above Earth’s
Surface
Contains Ozone (O3)
Layer
Temperature increases
with altitude.
Upper Layers
• Mesosphere
• Thermosphere
• Exosphere
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Mesosphere
• From Stratosphere to 80
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km (50mi) above
surface.
Temperature decreases
with altitude.
Layer in which most
meteors will burn up.
Ionosphere
• Layer of electrically
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charged particles.
Contained within the
mesosphere and
thermosphere.
Allows radio waves to
travel across the
country.
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Thermosphere
• Extends to from
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mesosphere to 500km
Contains the Auroras
Thickest of the layers
Temperature varies
greatly based on solar
energy.
Can heat up to 1,500°C
or higher
Exosphere
• Outermost layer
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extending to 800 km.
Where satellites and
shuttles orbit the Earth.
Contains very few
molecules
Ozone Layer
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Contained within the stratosphere.
It helps to protect us from the sun’s rays.
Located 19-48 km above us.
Made of ozone (O ).
Destroyed by CFC’s.
Hole in the ozone layer is increasing each year.
When the ozone layer disappears there will be
more cases of skin cancer.
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Student’s Created
Assignment
• Draw the layers of the atmosphere.
• Label each layer with the following:
– Name
– Range (distance from Earth’s Surface)
– Characteristics
– Temperature Range (Page 439)