1. The Atmosphere

2. The atmosphere of Earth is a layer of gases surrounding the planet
Earth that is retained by Earth’s gravity. The atmosphere protects life
on Earth by absorbing ultraviolet solar radiation, warming the
surface through heat retention (greenhouse effect), and reducing
temperature extremes between day and night.

3. Composition of air
Air is the name given to atmosphere used
in breathing and photosynthesis.

4. The Atmosphere
______ The
temperature in
the
atmosphere
______ varies
depending on
the different
______ layer we are
in.
______

5. Exosphere
Thermosphere
Mesosphere
Stratosphere
Troposphere

6. The Troposphere (I)
• It is the lowest level of
earth’s atmosphere where
the right mixture of oxygen
and nitrogen works to
support life.
• Here, living things are also free from the radiation showers
which flow down through most of the earth’s atmosphere.
• Compared to the rest of the atmosphere, the troposphere is a tiny
layer, extending at most 16km up from the earth’s surface. Within
this small layer almost all of our weather is created.

7. The Troposphere (II)
• Generally, as altitude increases, temperature decreases steadily.
But the earth's topography—mountain ranges and plateaus—can
cause some lower regions in the troposphere to experience
temperature inversions.
• Towards the top of the
troposphere temperatures
fall to an average low of -
57 ºC and wind speeds
increase significantly,
making the top of the
troposphere an extremely
cold and windy place.

8. The Stratosphere (I)
• The gradual change from the
troposphere to the stratosphere
begins at approximately 11km
high. The temperature in the
lower stratosphere is extremely
stable and cold at -57 ºC.
• There are strong winds. High
cirrus clouds sometimes form
in the lower stratosphere, but
for the most part there are no
significant weather patterns in
the stratosphere.

9. The Stratosphere (II)
• From the middle of the stratosphere and up, the temperature
pattern undergoes a sudden change, sharply increasing with
height. Much of this temperature change is due to increasing
levels of ozone concentration which absorbs ultraviolet
radiation.
• The temperature can
reach 18 ºC in the upper
stratosphere near an
altitude of 40km high.

10. The Mesosphere
• 40km above the earth’s surface marks the transition to the
mesosphere. In this layer, temperature once again begins to fall
as altitude increases, to temperatures as low as -143 ºC near its
top, 81km above the earth.
• Such extreme cold allows
the formation of so-called
noctilucent clouds, made of
ice crystals clinging to dust
particles.

11. The Thermosphere
• It directly above the mesosphere and directly below the
exosphere. Within this layer, ultraviolet radiation causes
ionization.
• Thermospheric temperatures increase with altitude due to
absorption of highly energetic solar radiation by the small amount
of residual oxygen still present. Temperatures can rise to 2,000°C.
• Radiation causes the
scattered air particles in
this layer to become
charged electrically
enabling radio waves to
bounce off and be
received beyond the
horizon.

12. The Exosphere
• The exosphere is the uppermost
layer of the atmosphere.
• In the exosphere, an upward
travelling molecule moving fast
enough to attain escape velocity
can escape to space; if it is
moving below escape velocity it
will be prevented from escaping
by gravity.

13. The greenhouse effect
is a process by which
radiation from the
surface of the Earth is
absorbed by
atmospheric gases, and
is re-radiated in all
directions.
Since part of this re-radiation is back towards the surface, energy is
transferred to the surface and the lower atmosphere. As a result, the
temperature there is higher than it would be if direct heating by solar
radiation were the only warming mechanism.

14. Earth

15. Earth is the third planet from
the Sun, and the densest and fifth-
largest of the eight planets in
the Solar System. It is also the
largest of the Solar System's four
terrestrial planets. It is sometimes
referred to as the world, the Blue
Planet, or by its Latin name, Terra.

16. Prepared by:
Kathlen F.Mauyao
BEED III B