1. LAYERS OF THE EARTH’S ATMOSPHERE

3. Layers of the Earth’s Atmosphere From top to Bottom
Exosphere
Thermosphere
Mesopause
Mesosphere
Stratopause
Stratosphere
Tropopause
Troposphere

5. TROPOSPHERE Lowest and thinnest layer 90% of the atmosphere’s mass
16 km (6 miles) at equator, 8 km at poles
90% of the atmosphere’s mass
Temperature decreases with altitude
6°C per kilometer
Top of troposphere averages
–50°C
Where weather occurs
Boundary between the troposphere, and the stratosphere is called the tropopause

7. STRATOSPHERE Extends from 10 km to 50 km above the ground (30 miles)
Less dense (less water vapor)
Temperature increases with altitude
Almost no weather occurrence
Contains high level of ozone
> ozone layer
Upper boundary is called stratopause

9. MESOSPHERE Extends to almost 80 km high (50 miles)
Gases are less dense.
Temperature decreases as altitude increases.
Gases in this layer absorb very little UV radiation.

11. THERMOSPHERE reflects radio waves
above the mesosphere and extends to almost 600 km (375 miles) high
temperature increases with altitude
readily absorbs solar radiation
Temperature can go as high as 1,500 °C
reflects radio waves

13. EXOSPHERE the interface between Earth and space
atoms and molecules can escape to space

14. How to remember them? The Stupid Monkeys Tattled on Elephants
Typical, Super Mario’s Time Expired!
The Smart Man Takes the Elevator
Exosphere
Thermosphere
Mesosphere
Stratosphere
Troposphere

15. Just add Oxygen? Earth was formed about 4.6 Billion years ago.
The first half of Earth's history was devoid of oxygen, but it was far from lifeless.
Most scientists believe the amount of atmospheric oxygen was insignificant up until about 2.4 billion years ago when the Great Oxidation Event (GOE) occurred.

16. This seemingly sudden jump in oxygen levels was almost certainly due to cyanobacteria – photosynthesizing microbes that exhale oxygen.
When and how the oxygen-exhalers appeared is uncertain, due to the fact that the GOE was a complicated crossroads of global freezing, mineral upheavals and the flourishing of new species.
Oxygen was continued to be released into the atmosphere until it made up 20.9 percent of the atmosphere.