1. The Atmosphere

2. Characteristics of the Atmosphere
It is a blanket of moisture-filled air that surrounds the earth
It consists 78% nitrogen, 21% oxygen, 1% other gases (argon, carbon dioxide and water)
It has ozone in its upper layers which absorb harmful UV rays from the sun
It protects us from meteors (they vaporize due to the friction with the atmosphere) SEE ALBERTA CLIP
It keeps the earth warm enough for us to live
BRRRRRR!! DO YOU KNOW HOW COLD SPACE IS???

3. Layers of THE Atmosphere

4. Temperature Gradient
Temperature Gradient: A change in temperature over a vertical distance
In the troposphere, the temperature gradient is -0.65° per m in altitude
Q: What is the temperature at the top of an 8000 m mountain if the temperature is 18°C at the foot of the mountain?
A. -34°C !!!

5. Layers Again….

6. Layers in Order…(FROM EARTH TO SPACE)
1. Troposphere – up approx 12 km
Closest to the Earth’s surface
Where all weather takes place
Air is in constant motion with both vertical and horizontal currents
Pressure decreases as altitude increases
Has very small amounts of ozone
2. Tropopause
Contains more ozone than troposphere
Is warmer than the troposphere because it absorbs UV rays from the sun

7. 3.STRATOSPHERE
12-50 km above the Earth’s surface
Higher levels of ozone than any other layer
4.MESOSPHERE
Temperatures are very low here
50 to 80 km above the earth
Very low density
Meteors from space usually burn up in this layer due to air friction

8. 5.Thermosphere (Ionosphere)
80 km to 500 km from Earth’s surface
Fewest air molecules
Also called ionosphere b/c the Sun’s radiation causes particles to become electrically charged ions
The Northern and Southern lights (aurora borealis) are produced by these ions
These charged particles also reflect radio signals so they can travel around the World

9. 6. Exosphere Outer limits! SPACE The thin, outermost layer
Very few particles (hydrogen) spread out very far
- DISCOVERY COMMERCIAL

10. Atmospheric Layers: Scale Diagram Activity
 You will be producing a diagram of the atmospheric layers. These layers will be proportional in thickness to each other.
Troposphere 0 – 12 km
Tropopause 12 – 16 km
Stratosphere 16 – 50 km
Mesosphere 50 – 80 km
Thermosphere 80 – 500 km
Exosphere ??? Km

11.  Your scale will be 1 cm = 10 km
Obtain 4 or 5 strips of paper from the teacher.
Start by representing the surface of the Earth and then proceed upwards through the layers.
Use the thickness of the layers and the given scale to draw your diagram.
Clearly label all distances (in km) and label all atmospheric layers in their proper location.
Represent important information about each layer.
Use color.
Be neat and tidy.