Chapter 15, Section 4 By Stephanie Lund September 27, 2005 T4

Quick Notes  Inner or lowest layer of Earth’s atmosphere  Weather occurs here  Contains almost all of the mass in the atmosphere  Starts at the Earth’s surface and extends anywhere between 8 and 16 kilometers above Earth  The air at the top is about -60 degrees, Celsius Question Question Why do you think the clouds at the top of the Troposphere are made of ice crystals and not drops of water?

The Quick Notes Extends from the top of the Troposphere to about 50K above Earth’s surface Extends from the top of the Troposphere to about 50K above Earth’s surface The lower stratosphere is warmer than the upper troposphere The lower stratosphere is warmer than the upper troposphere A large amount of ozone is found here, it absorbs ultraviolet radiation from the sun A large amount of ozone is found here, it absorbs ultraviolet radiation from the sun Question Do you know what ultraviolet radiation is?

The The Quick Notes o o “Meso” means middle and the mesosphere is the middle layer of the Atmosphere o Starts at 50k above earth and ends at 80K o Protects earth from being hit by meteorites (chunks of stone and Metal) Question What is the depth of the Mesosphere?

The Quick Notes   Starts at 80k above Earth and extends all the way to space   Air is.001% as dense as the air at sea level   Outermost layer of the atmosphere   The Thermosphere is broken up into two parts: The Ionosphere and The Exosphere   Ionosphere-The Aurora Borealis occurs here. It is caused by particles from the sun entering the Ionosphere near the North Pole   Exosphere- when you make a phone call or listen to the radio the signal travels up to satellites that are orbiting the Exosphere

Review Questions After reading this Power Point you should be able to answer these 6 questions: 1. What are the characteristics of the main layers of the atmosphere (not including the Ionosphere and the Exosphere) ? 2. In which layer of the atmosphere do rain, snow, storms, and most clouds occur? 3. Ozone absorbs energy from the sun in which layer of the atmosphere? 4. In what layer of the atmosphere do most meteoroids burn up in? 5. Where does the Aurora Borealis occur? 6. In which layer of the atmosphere do communication satellites orbit Earth?

Bibliography m m Science Explorer Earth Science. New Jersey: Prentice-Hall, Inc.

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