1. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Big Picture MS-ESS2-5. Collect data to provide evidence for how the motions and complex interactions of air masses results in changes in weather conditions.

2. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Characteristics of the Atmosphere Bellringer List the ways that the atmosphere is different from outer space. Write your list in your science journal. Chapter I1

3. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Characteristics of the Atmosphere Objectives Describe the composition of Earth’s atmosphere. Explain why air pressure changes with altitude. Explain how air temperature changes with atmospheric composition. Describe the layers of the atmosphere. Chapter I1

4. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Agenda Today we will: –Day 1: Do now –Teacher power point with notes. –Exit ticket –Day 2: Station activities Exit ticket.

5. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Vocabulary Atmosphere Air pressure troposphere stratosphere mesosphere thermosphere ionosphere

6. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Characteristics of the Atmosphere The Composition of the Atmosphere The atmosphere is made up mostly of nitrogen gas. Oxygen makes up a little more than 20% of the atmosphere. Chapter I1

7. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Characteristics of the Atmosphere Atmospheric Pressure and Temperature The atmosphere is held around the Earth by gravity. Gravity pulls gas molecules in the atmosphere toward the Earth’s surface, causing air pressure. As altitude increases, air pressure decreases. Air temperature decreases as altitude increases. Lower parts of the atmosphere are warmer because they contain a high percentage of gases that absorb solar energy. Chapter I1

8. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Characteristics of the Atmosphere Layers of the Atmosphere The Troposphere: The Layer in Which We Live The lowest layer of the atmosphere, which lies next to the Earth’s surface, is called the troposphere. The Stratosphere: Home of the Ozone Layer The atmospheric layer above the troposphere is called the stratosphere. The Mesosphere: The Middle Layer The mesosphere is the middle layer of the atmosphere. It is also the coldest layer. Chapter I1

9. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Characteristics of the Atmosphere Layers of the Atmosphere, continued The Thermosphere: The Edge of the Atmosphere The uppermost atmospheric layer is called the thermosphere. The Ionosphere: Home of the Auroras In the upper mesosphere and the lower thermosphere, nitrogen and oxygen atoms absorb harmful solar energy. This area is called the ionosphere. Chapter I1

10. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Characteristics of the Atmosphere Chapter I1

11. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Exit Ticket What are the layers of the atmosphere in order from closest to Earth’s surface to space?