Page 91 - Science Course 1 (Book 2)
P. 91
Mo9-L1b: What is the Atmosphere?
In the bottom layer of the atmosphere, called the The stratosphere is above the troposphere. In the
troposphere, temperature decreases as you move stratosphere, gases are more stable and form f at
upward from Earth’s surface. Gases f ow and swirl in layers.
the troposphere, causing weather.
The mesosphere is above the stratosphere. In the mesosphere, the air temperature decreases with increasing
altitude.
Temperatures increase again as you move further from Earth’s surface through the next layer, the thermo-
sphere.
The outer layer of Earth’s atmosphere is the exosphere.
Key Concept SUMMARY
What is the Atmosphere?
What is the Atmosphere?
The atmosphere is made mainly of gases and
What are the layers of the atmosphere? has a layered structure.
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