1. Warm-up
How is the atmosphere important to the survival of life on Earth?

2. Layers of Earth’s Atmosphere
S6E4. OBTAIN, EVALUATE, and COMMUNICATE information about how the sun, land, and water affect climate and weather.
ANALYZE and INTERPRET data to COMPARE and CONTRAST the composition of Earth’s atmospheric layers (including the ozone layer) and greenhouse gases.
(Earth’s atmospheric layers include the troposphere, stratosphere, mesosphere, and thermosphere.)

3. How was the atmosphere formed?
The atmosphere has changed (evolved) over time.
Gases are held near the surface by gravity.
Earth’s early atmosphere was “outgassed” from the interior through release of gasses and volcanic eruptions.
Many factors, such as solar radiation and photosynthesis, helped the atmosphere to develop into what we enjoy today.

4. Troposphere Layer closest to the Earth 0- 10 km (0 – 5 miles)
People, plants and animals exist here
Clouds, storms, precipitation are in this layer
Temperature decreases (gets colder) as altitude increases

5. Stratosphere Starts at the top of troposphere 20 - 50 km
( miles)
Where most jets fly
Ozone layer is found here
Temperature increases (gets warmer) with altitude because ozone absorbs UV rays which warm the air

6. Mesosphere 50 – 80 km (30 – 50 miles) above the Earth’s surface
Coldest layer of the atmosphere
Temperature decreases with altitude
Meteors burn at this layer

7. Thermosphere Temperature increases with altitude
90km (60 miles) above Earth’s surface
Hottest layer – degrees
Air is so thin that temperature cannot be measured with a thermometer but as motion of the few particles that are there.
Divided into two sublayers:
Exosphere and Ionosphere

8. Exosphere
Top of the thermosphere
Satellites orbit here

9. Ionosphere Auroras occur here
Radio waves are reflected back to Earth from this layer
Sun’s energy breaks apart atoms into IONS at this level

10. How is the atmosphere important to the survival of life on Earth?
Warm-up revisited
e3cd-4cc9-ab59-bd7d8a977cf6/?hasLocalHost=True – Earth’s atmosphere
(Revise warm-up and complete TOD)
How is the atmosphere important to the survival of life on Earth?