1. Characteristics of the Atmosphere Jeanne Omvig Maple Lake High School

2. Atmopshere The atmosphere is a mixture of gases that surrounds Earth Oxygen as well as several other gases including carbon dioxide and nitrogen It also protects us from the harmful rays of the sun Water in the form of water vapor

3. Atmospheric pressure Air may not feel that heavy but it does add up. After sea level –a square inch is of surface area is almost 15lbs of air. Carrying that much air on such a small surface area is like carrying a large bowling ball on the tip of your finger

4. As altitude increases, Air pressure decreases Air Pressure-is the measure of the force with which air molecules push on a surface. – As you move away from the Earth’s surface, fewer gas molecules are pushing down on you therefore the pressure or weight goes down. You can think of it as a pyramid

5. Atmospheric Composition affects Air Temperature Air temperature also changes as altitude increases. The temperature differences result mainly from the way solar energy is absorbed as it moves through the atmosphere. Some of the atmosphere are warmer because it contains a high percentage of gases that absorb solar energy

6. Layers of the Atmosphere Troposphere-the lowest layer, temperature decreases at a constant rate as altitude increases – Layer we live – Contains 90% of the total mass of the atmosphere Stratosphere-the layer of the atmosphere above the troposphere, in which temp. increases as altitude increases. – Home of the ozone layer – Contains little moisture – Average temp is -60̊C

7. Layers Cont. Mesosphere- the layer of the atmosphere between the stratosphere and the thermosphere, in which temperature decreases as altitude increases. – The Middle Layer – Temps can be as low as -93̊C

8. Layers Cont. Mesosphere- the layer of the atmosphere between the stratosphere and the thermosphere, in which temperature decreases as altitude increases – Coldest layer – Middle Layer Thermosphere- The upper most layer of the atmosphere, in which temperature increases as altitude increases – Temp here can reach 1000̊C or higher – Low density-cannot transfer much energy

9. Layers Cont. Ionosphere- is a name for the layer of the earth's atmosphere that is ionized by solar radiation. – The Auroras are located here – It is located in the lower thermosphere and the upper mesosphere.

10. Review Quiz What are the layers of the atmosphere? Name one fact about each layer.