Atmosphere Notes

1
Atmosphere Notes
2
What are the properties of air?

• Mass air consists of atoms and molecules.
• Density the amount of mass in a given volume of
  air.
• Pressure the force pushing on an area or
  surface.

3
What is the atmosphere?

• The layer of gases that surround the planet.
• Earths atmosphere makes conditions on Earth
  suitable for living things.

4
Composition?
78 nitrogen, 21 oxygen, and 1 argon and other
gases.
5
Whats in the other 1 ?

• Argon gas
• Greenhouse Gases like
• carbon dioxide
• water vapor
• methane
• and more

6
Atmospheric Pressure

• Air pressure is greater near the Earths surface.
  This is because there are more molecules in the
  air near the Earths surface than at the top of
  the atmosphere.
• As you move up from sea level, air pressure
  decreases because there is less density of
  particles.

7
Atmospheric Pressure

• Heated Air Less Dense and exerts a lower
  pressure
• Colder Air Higher density of molecules and
  exerts a higher pressure.

8
What is a barometer?

• A barometer is the instrument we use to measure
  air pressure.
• Read pages 510-511, fill in definitions on your
  notes.

9
Air pressure and altitude

• Altitude is your height above sea level.
• Higher altitudelow pressure
• Lower altitudehigher pressure

Thats why its colder higher in the troposphere
(bottom layer).
Mount Charleston, Nevada
10
(No Transcript)
11
Troposphere
0-12 km

• Layer of the atmosphere closest to the Earth's
  surface
• Tropo means turning or changing.
• It contains 75 of the atmosphere's mass
• Temperature and pressure decrease as you go
  higher up the troposphere
• Where weather occurs

12
Stratosphere
12-50 km

• Layer directly above the troposphere
• Strato means layer or spreading out.
• Lower portion of the stratosphere has the ozone
  layer.
• This temperature increase with altitude is the
  opposite of the situation in the troposphere
• Airplanes travel here

13
Ozone Layer

• The ozone layer protects us from ultraviolet
  radiation.
• The ozone layer absorbs most of the suns UV
  radiation before they reach us.

• As the radiation is absorbed, the earths
  atmosphere heats up.

14
Ozone is good in the upper atmosphere, but it is
NOT good to breathe.
OXYGEN
OZONE
15
Scientists study the ozone layer.
16
One group of gases is particularly damaging to
the ozone layer. These gases are called CFCs,
(Chloro-Fluoro-Carbons). CFCs destroy ozone
molecules.
Most countries have started using different
substances in place of CFCs and the whole in the
ozone layer is shrinking.
17
Mesosphere
50-80 km

• cold layer of the atmosphere, directly above the
  stratosphere
• Meso means middle
• temperature generally decreases with increasing
  altitude
• Meteors burn up in this layer

18
Thermosphere
80 km and up

• temperature is hot and may be as high as
  thousands of degrees
• Thermo means heat
• Very few molecules in this layer
• Divided into the Ionosphere and the Exosphere.

19
Ionosphere
80 550 km

• This layer contains ions (electrically charged
  particles.
• Auroras occur here because particles from the sun
  enter the ionosphere near the poles and they
  strike the nitrogen and oxygen making them
  electrically charged. This causes the molecules
  to glow.

20
Exosphere
550 km and up

• Exo means outer
• Satellites the space station orbit here
• This layer does not have a distinct end, but
  instead just merges into outer space.

21
(No Transcript)