Definition of the Atmosphere
The layer of gases surrounding Earth;
composed mainly of 78% nitrogen and 21%
oxygen, and other gases (water vapor, dust,
Layers of the Atmosphere
• There are different layers:
• Each layer has a different temperature
• Different things take place or are found in
• Between each layer of the atmosphere is a
• These boundaries are called pauses:
• At these "pauses," maximum change
between the "spheres" occur.
– Above the troposphere is the tropopause;
– above the stratosphere is the stratopause;
– above the mesosphere is the mesopause; and
– above the thermosphere is the thermopause.
• The layer of the atmosphere closest to the
earth is the troposphere.
• This layer is where weather occurs.
• It begins at the surface of the earth and
extends out to about 4-12 miles.
• Contains 80% of all the mass of the
atmosphere and almost all the water vapor.
Temperature decreases as you rise.
• The temperature of the troposphere
decreases with height.
• This layer is known as the lower
• Stratosphere- Jet planes often fly in the
lower levels of this layer because it is
above the weather.
• This layer contains most of the ozone
• People can not breathe in this layer.
• Extends to about 30-35 miles above the
• Temperature rises within the stratosphere
because of the ozone layer but still
remains well below freezing.
• Pale, blue gas with a strong odor. O3
• Ozone is extremely important because it is
the only gas that absorbs ultraviolet (UV)
radiation from the Sun and protects the
surface of the Earth and people from the
damaging effects of UV rays.
• The ozone layer filters out ultra violet light.
This protects us from severe burning from
• Temperature increases as you rise.
• 90% of ozone layer in stratosphere; 10% in
• Air is especially thin and molecules
are great distances apart.
• This is where we see "falling stars" –
meteors burning up as they fall to
• Temperature decreases as your rise.
• About 35 to 50 miles above the
surface of the Earth
• Layer of the atmosphere which is first exposed to the Sun's
radiation and so is first heated by the Sun.
• Rises several hundred miles above the earth's surface, from
50 miles up to about 400 miles.
• Temperature increases with height and can rise to as high as
3,600Â°F (2000Â°C) but the air would feel cold because the
hot molecules are so far apart.
• Contains a working station for astronauts. The space shuttle
orbits in the thermosphere.
• Made up of Ionosphere & exosphere
Ionosphere- lower part of thermosphere; contains electrically
charged particles known as ions & Inner Van Allen radiation
belt; allows the reflection of radio waves for world wide radio
Exosphere- Highest layer of atmosphere; farthest layer from
earth; limits of this layer are not exactly known. Atoms and
molecules escape into space
a.k.a The Northern Lights
or Aurora Borealis
• The beautiful blaze of the
Northern Lights, or Aurora
Borealis, is caused when
material thrown off the
surface of the sun collides
with the atmosphere of the
• When the particles collide
with the gases in the
ionosphere they start to
glow, producing an array of
colors consists of red,
green, blue and violet.
• Can see them from the polar
• Observed in the ionosphere.
Click here for animation
• The atmosphere is divided into five
layers. It is thickest near the surface
and thins out with height until it
eventually merges with space.
• 1) The troposphere is the first layer
above the surface and contains half
of the Earth's atmosphere. Weather
occurs in this layer.
2) Many jet aircrafts fly in the
stratosphere because it is very
stable. Also, the ozone layer absorbs
harmful rays from the Sun.
3) Meteors or rock fragments burn up
in the mesosphere.
4) The thermosphere is a layer with
auroras. It is also where the space
5) The atmosphere merges into
space in the extremely thin
exosphere. This is the upper limit of