1. Layers of the Atmosphere
The layer of gases that surrounds the Earth
Forms a protective boundary between Earth and space
Provides conditions suitable for life

2. Composition of Atmosphere
Nitrogen %
Oxygen %
Water Vapor – 0 to 4%
Carbon Dioxide %
Other gases make up the rest

4. Atmospheric Gases
Nitrogen, oxygen, argon, water vapor, carbon dioxide, and most other gases are invisible.
Clouds are not gas, but condensed vapor in the form of liquid droplets.
Ground based smog, which is visible, contains reactants of nitrogen and ozone.
Write “Condensation” on the board: The changing of water vapor to liquid water
Write “evaporation” on the board : The process of liquid water becoming a gas
Water Vapor is extremely important in our atmosphere.
Not only does it form it precip,
Also releases large amounts of heat – called latent heat when it changes from vapro to liquid water or ice.
Latent hear is an important source of atmospheric energy especially for thunderstorms and hurricanes.
Also is one of our greenhouse gases – absorbs a portion of the earth’s outgoing radiant energy thus playing big role in the earth’s energy balance
Ozone – is the primary ingredient of smog!

5. TROPOSPHERE We live in the Troposphere – nearest to Earth
The gases in this region are mainly O2 and N2
The highest mountains are still within the troposphere
All of our normal day-to-day activities occur here.
The jet stream is found near the tropopause at the upper end of this region.
Temperature drops as altitude increases
Up to approximately 12 km
All weather is here
contains 90% of the Earth's atmosphere
Contains 99% of the water vapor

6. STRATOSPHERE Ozone (O3) layer is here Hot air balloons fly here
Absorbs UV radiation from the sun
Hot air balloons fly here
Helium balloons fly here
This layer holds 19 % of the atmosphere's gases and but very little water vapor
Approximately km high
Temperature INCREASES with altitude
Jets fly here  air is stable

7. Atmospheric Greenhouse Effect
The warming of the atmosphere by its absorbing and emitting infrared radiation while allowing shortwave radiation to pass through. The gases mainly responsible for the earth’s atmospheric greenhouse effect are water vapor and carbon dioxide.

8. MESOSPHERE (in the Middle)
The gases, including O2, continue to become thinner with height
Meteors burn up here
Radio waves reflected to Earth in this layer
Temperature decreases as altitude increases

9. THERMOSPHERE
Only the higher energy UV and x-ray radiation from the sun is absorbed
Temperature increases as altitude increases
HOTTEST layer
Ionosphere is part of the this layer
Aurora Borealis
Highly charged particles give off colored photons of energy in the sky

11. EXOSPHERE Outermost layer of the atmosphere
Satellites orbit the earth in this layer
Temperature increases with altitude

13. Vertical Pressure Profile
Atmospheric pressure decreases rapidly with height. Climbing to an altitude of only 5.5 km where the pressure is 500 mb, would put you above one-half of the atmosphere’s molecules.
This igure shows how rapidly air pressure decreases with height.
Near sea level, atmospsheric presssure decreases rapidly, whereas at high levels it decreases more slowly.
At about 3.5 mi up air pressure is approx. 500 mb or about ½ of sea level pressure
This means that if you were at about 18,000 feet above the surface you would be above one half of all the molecules in the atmosphere.
The top of Mt Everest (29,000 ft) has a pressure of about 300 mb. The summit of the mountain is above about 70% of all the molecules in the atmosphere.
If you go up to about 50 km (about 164,000 ft) the air pressure is about 1 mb which means that 99.9 % of all molecules are below this level.