1. Layers of the Atmosphere

2. What is the Atmosphere? A mixture of gases and other materials that surround the Earth Nitrogen 78% Oxygen 21% Argon 0.93% Carbon dioxide 0.03%

3. Earth’s Atmosphere Earth, our home planet, is the only planet in our solar system known to harbor life. Only 30% of the sun’s energy that reaches the Earth is reflected back into space by clouds. Earth’s atmosphere is held in place by gravity. Divided into layers based on differences of temperature.

4. Layers of the Atmosphere 1. Troposphere 2. Stratosphere 3. Mesosphere 4. Thermosphere 5. Exosphere

5. Troposphere

6. Stratosphere

7. Ozone Layer Thin band in the top of the stratosphere Blocks out the sun’s harmful ultra-violet (UV) rays Ozone is made up of 3 oxygen atoms Earth's ozone layer averages about 3 millimeters (1/8 inch) thick, about the same as two pennies stacked one on top of the other

8. Ozone Hole Every spring, a hole as big as the USA develops in the ozone layer over Antarctica, in the South Pole. One group of gases is likely to damage the ozone layer, called CFC’s (chloro-fluoro-carbons). CFC’s are used in some spray cans to force the contents out of the can. They are also used in refrigerators, A/C, and fire extinguishers. Most countries have stopped using CFC’s.

9. Mesosphere 50-90 km (31-56 mi.) above the Earth Contains chemicals which absorb energy from the sun The top is the coldest part of the atmosphere with temperatures of near -90 Protects Earth’s surface from most meteoroids They burn up as they fall toward Earth

10. Thermosphere Outermost layer of Earth’s atmosphere 90 km (56 mi) and up Radiation from the sun heats the thermosphere causing the temperature to rise as you move up Temperatures up to 1,800 C Divided into 2 layers (ionosphere and exosphere)

11. Ionosphere & Exosphere Lower level – Ionosphere 1. gas molecules are electrically charged because of sun’s energy 2. Aurora borealis, or Northern Lights, occur in ionosphere Outer layer –Exosphere 1. satellites and space shuttles orbit Earth in this layer 2. Air pressure is low because there are so few molecules floating around

12. How can I remember all these layers? Troposphere Stratosphere Mesosphere Thermosphere Ionosphere Exosphere That Snake Must Think I’m Evil !!