Atmosphere

1
Atmosphere

• Notes

2
What is it?

• Atmosphere is a mixture of gases that surrounds
  Earth.
• Contains oxygen you breathe
• Protects from suns rays
• The atmosphere is always changing.
• It protects living things from radiation from the
  sun, and from being hit by chunks of most space
  rocks, like meteors and asteroids!!

3
Whats in it???

• Not what you think!
• 78 Nitrogen (N)
• 20.95 Oxygen (O)
• 0.93 Argon (Ar)
• 0.038 carbon dioxide (CO2)
• Trace amounts of other gases and dust
• About 1 water vapor

4
Gases in the Atmosphere
5
Water Vapor

• Water vapor in the air exists as liquid droplets,
  and solid water (snow and ice) and the rest is
  water vapor
• Water vapor is an invisible gas.

6
Air pressure

• Air pressure is the measure of the force with
  which air molecules push on a surface
• It is strongest at Earths surface because there
  is more air above you.
• As you go up in altitude, away from the sea
  level, fewer gas molecules are above you and air
  pressure decreases

7
Layers of the Atmosphere

• Based on temperature, divided into four main
  layers
• Each ends in sphere
• Tropo means turning or change since the
  troposphere is always changing
• Strato means layer since the layers do not mix
  there
• Meso means middle
• Thermo means heat since it is the hottest
• Exo means outside

8
Layers of the Atmosphere

• There are 4 layers in the atmosphere
• They are the troposphere, mesosphere,
  thermosphere, and stratosphere

9
Layers of the AtmosphereTroposphere

• This is the layer that is closest to the surface
  of the earth
• Its elevation ranges from 0 to 10 km
• Rain, snow, storms, and most clouds occur here.

10
Layers of the AtmosphereStratosphere

• This layer sits on top of the troposphere
• Its elevation ranges from 10 km to around 25 km
• This layer contains the ozone layer, which
  protects us from harmful sunlight

11
Layers of the AtmosphereMesosphere

• This layer is above the stratosphere
• Its elevation ranges from 25 to 100 km
• Most meteoroids burn up in this layer, producing
  meteor trails.

12
Layers of the AtmosphereThermosphere

• This is the highest layer of the atmosphere
• Its height ranges from 100km. It has not
  definite outer limit
• This is where most small meteorites burn up and
  is also the location in the atmosphere that the
  northern lights occur (aurora borealis)

13
Layers of the AtmosphereThermosphere
The aurora borealis is caused by particles from
the sun that enter the ionosphere near the North
Pole. These particles strike oxygen and nitrogen
atoms in the ionosphere, causing them to glow.

• Ionosphere
• Lower level of the thermosphere
• begins 80 kilometers above the surface and ends
  at 550 kilometers.
• Energy from the sun causes gas molecules in the
  ionosphere to become electrically charged
  particles called ions.
• Radio waves bounce off ions in the ionosphere and
  then bounce back to Earth's surface.

14
Layers of the AtmosphereThermosphere

• The Exosphere
• the outer layer of the thermosphere.
• The exosphere extends from 550 kilometers
  outward for thousands of kilometers
• When you make a long-distance phone call or watch
  television, the signal may have traveled up to a
  satellite orbiting in the exosphere and then back
  down to your home.
• Satellites are also used for watching the world's
  weather and carrying telescopes that look deep
  into space.

15
Layers of the Atmosphere Activity
16
Comprehension Check-TOTD

• Why does air pressure decrease as altitude
  increases?
• What two gases make up most of the atmosphere?
• What are the four main layers of the atmosphere?
• The layers of the atmosphere are classified
  according to changes in _________________.

17
Comprehension Check-TOTDAnswers

• Why does air pressure decrease as altitude
  increases?
• Air pressure decreases as altitude increases
  because fewer gas molecules are above you.

18
Comprehension Check-TOTDAnswers

• What two gases make up most of the atmosphere?
• Nitrogen and Oxygen

19
Comprehension Check-TOTDAnswers

• What are the four main layers of the atmosphere?
• Troposphere
• Stratosphere
• Mesosphere
• Thermosphere

20
Comprehension Check-TOTDAnswers

• The layers of the atmosphere are classified
  according to changes in _________________.
• Temperature