The document describes the layers of Earth's atmosphere. It begins with the troposphere, the lowest layer where weather occurs. Above this is the stratosphere, with an important ozone layer. Next is the mesosphere where meteors burn up. Higher is the thermosphere, home to satellites. The outermost layer is the exosphere, with very low density air at the edge of space. Temperature and pressure decrease with altitude as the atmosphere provides protection from solar radiation.

1. Earth’s Atmosphere
Illustrated by
Kella Randolph, M.Ed.
https://upload.wikimedia.org/wikipedia/commons/thumb/c/cf/Colorado_Springs_Hot_Air_Balloon_Competition.jpg/1200px-Colorado_Springs_Hot_Air_Balloon_Competition.jpg

2. The atmosphere is the air
that surrounds the earth.
• There are many gases found in
the atmosphere. The main gases are:
• Nitrogen - (78.1%) - dilutes the
oxygen and is used by living things to
make proteins
• Oxygen - (21%) - used by nearly
all living things for respiration
• Argon- (0.9%) - used in light bulbs
and double pane windows
• Carbon dioxide - (0.035%) - used
by plants to make oxygen, serves as
a blanket for earth to hold in heat
• Many other gases are present but
in very small amounts.
Image: http://4.bp.blogspot.com/-
QwxgvAIShNw/USx4iQZrSCI/AAAAAAAAFPM/l25hYoukGj0/s640/i
mage253.gif

3. We have lots of
water vapor in our
atmosphere.
Water vapor is water but in a gas state -
evaporated water - and can account for up to
4%.
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4. Our atmosphere has
pauses between the five
layers.
• Each of these layers has a
different composition, temperature
and density. Between each layer is
also a pause, an area where we see
the biggest changes in these
characteristics.
https://static.skepticalscience.com/images/atmosphere_layers.jpg

5. Earth’s atmosphere
There are five layers.
Beginning on the ground and going up the
layers are:
1. Troposphere
2. Stratosphere
3. Mesosphere
4. Thermosphere
5. Exosphere
http://2.bp.blogspot.com/-JrP4NV6eztA/UpTm77tiJRI/AAAAAAAAKkM/jrcKbnK9eoY/s1600/atmosphere.jpg

6. Troposphere.
Closest to the surface of the Earth is the Troposphere.
● where all weather occurs
● extends 4 - 12 miles from the surface
● temperature decreases
Closest to the surface of Earth, we have the troposphere.
“Tropos” means change. This layer gets its name from the
weather that is constantly changing and mixing up the gases in
this part of our atmosphere.
The troposphere is between 5 and 9 miles (8 and 14 kilometers)
thick depending on where you are on Earth. It’s thinnest at the
North and South Pole.
This layer has the air we breathe and the clouds in the sky. The air
is densest in this lowest layer. In fact, the troposphere contains
three-quarters of the mass of the entire atmosphere. The air here
is 78% nitrogen and 21% oxygen. The last 1% is made of argon,
water vapor, and carbon dioxide.
When you feel the wind on your face, see clouds in the sky, and
watch a bird flap its wings in flight, you’re experiencing the
troposphere. It’s a pretty nice layer to call home. Text from NASA
https://spaceplace.nasa.gov/troposphere/en/
Image: https://spaceplace.nasa.gov/troposphere/en/tropo.en.png

7. Stratosphere
Next layer moving inward is the Stratosphere
● extends from the Troposphere to 31 miles
above the surface
● temperature decreases (moving away from the
surface)
“Strat” means layer. This layer of our atmosphere has its
own set of layers. There are no storms or turbulence here to
mix up the air, so cold, heavy air is at the bottom and warm,
light air is at the top. That’s the opposite of how the layers
work in the troposphere, where we live. If you were to climb
a mountain in the stratosphere you would have to take off
your warm clothes as you got closer to the top rather than
putting them on like we usually do. But there are no
mountains high enough to reach the stratosphere, so you
don’t have to worry about that.
This layer is 22 miles (35 kilometers) thick. The stratosphere
is where you’ll find the very important ozone layer. The
ozone layer helps protect us from ultraviolet radiation (UV)
from the sun. In fact, the ozone layer absorbs most of the
UV radiation the sun sends to us. Life as we know it
wouldn’t be possible without this layer of protection. Text
from NASA https://spaceplace.nasa.gov/stratosphere/en/
Image:https://spaceplace.nasa.gov/stratosphere/en/strato.e
n.png

8. Mesosphere
Below the Thermosphere is the Mesosphere
● extends from 31 miles to 53 miles above the
surface
● temperature decreases (moving toward space)
● Gasses are dense enough now to slow meteors
The mesosphere is 22 miles (35 kilometers) thick.
The air is still thin, so you wouldn’t be able to
breathe up in the mesosphere. But there is more
gas in this layer than there is out in the
thermosphere.
Have you ever seen a meteor shower, where
meteors burn up and streak across the sky? Some
people call them shooting stars. Those meteors are
burning up in the mesosphere. The meteors make it
through the exosphere and thermosphere without
much trouble because those layers don’t have
much air. But when they hit the mesosphere, there
are enough gases to cause friction and create heat.
Text from NASA
https://spaceplace.nasa.gov/mesosphere/en/
Image: https://spaceplace.nasa.gov/mesosphere/en/meso.en.png

9. Thermosphere
The Thermosphere
● exists between 53 miles and 375 miles above earth
● air is still thin but becomes more dense moving closer to
earth
● temperature increases as you increase height due to
absorbed UV and x-ray radiation
The thermosphere lies between the exosphere and the
mesosphere. “Thermo” means heat, and the temperature in this
layer can reach up to 4,500 degrees Fahrenheit. If you were to
hang out in the thermosphere, though, you would be very cold
because there aren’t enough gas molecules to transfer the heat
to you. This also means there aren’t enough molecules for sound
waves to travel through.
This layer of Earth’s atmosphere is about 319 miles (513
kilometers) thick. That’s much thicker than the inner layers of the
atmosphere, but not nearly as thick as the exosphere.
The thermosphere is home to the International Space Station as it
orbits Earth. This is also where you’ll find low Earth orbit
satellites. There’s a lot going on in the thermosphere! Text from
NASA https://spaceplace.nasa.gov/troposphere/en/
● Image: https://spaceplace.nasa.gov/thermosphere/en/thermo.en.png

10. Exosphere
• The Exosphere is the outermost layer.
• extends from 375 to 6200 miles above the earth
• air density is very low and molecules escape into space
• The outermost layer
• The exosphere is the outermost layer of our atmosphere. “Exo” means outside
and is the same prefix used to describe insects like grasshoppers that have a hard
shell or “exoskeleton” on the outside of their body.
•
The exosphere is the very edge of our atmosphere. This layer separates the rest of
the atmosphere from outer space. It’s about 6,200 miles (10,000 kilometers) thick.
That’s almost as wide as Earth itself. The exosphere is really, really big. That means
that to get to outer space, you have to be really far from Earth.
•
The exosphere has gases like hydrogen and helium, but they are very spread out.
There is a lot of empty space in between. There is no air to breathe, and it’s very
cold. Text from NASA https://spaceplace.nasa.gov/exosphere/en/
• Image: https://spaceplace.nasa.gov/exosphere/en/exo.en.png

11. What is the ionosphere?
• The ionosphere is a very active part of the atmosphere, and
it grows and shrinks depending on the energy it absorbs from
the Sun. The name ionosphere comes from the fact that gases
in these layers are excited by solar radiation to form ions,
which have an electrical charge. Text from NASA
https://spaceplace.nasa.gov/ionosphere/en/
Image: https://spaceplace.nasa.gov/ionosphere/en/ionos.en.png

12. Temperature and density changes
• As you travel up through the
atmosphere, moving toward space,
the temperature changes and the
air pressure decreases and
becomes thinner.
http://i.stack.imgur.com/bny3F.gif

13. Air pressure
• Air pressure is the measure of molecules in a particular space.
In the atmosphere, the pressure of air changes depending on the
layer. Let’s look at the pressure in the Troposphere. As we climb in
elevation, the air pressure decreases. This is why when you climb
a mountain, it becomes harder to breath. There are less air
molecules near the top of the Troposphere.
• Air pressure is usually measured using a barometer and
recorded in “inches of Mercury” or “Millibars”.
https://upload.wikimedia.org/wikipedia/commons/4/4c/Aneroid_barometer.JPG
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14. The sun lights and heats
the earth.
• The sun supplies all the heat for our planet. The energy from the sunlight travels
through space and our atmosphere. When it reaches the surface, some is
transferred to heat.
• _Radiant heat is what you feel when the sun has warmed the road and makes it
impossible to walk barefoot in the summer. The sunlight reaches the road and the
energy is absorbed. Radiant energy is how we keep food warm with heat lamps.
• Once the sun’s rays reach the earth’s surface, the air immediately above the
ground warms. This process is called convection.
• The warmed air begins to rise to higher altitudes. This movement of warm air is
called convection.
https://upload.wikimedia.org/wikipedia/commons/thumb/b/bb/The-NASA-Earth%27s-Energy-Budget-
Poster-Radiant-Energy-System-satellite-infrared-radiation-fluxes.jpg/1200px-The-NASA-Earth%27s-
Energy-Budget-Poster-Radiant-Energy-System-satellite-infrared-radiation-fluxes.jpg
http://i.stack.imgur.com/1LHed.jpg

15. Radiant heat
• _Radiant heat is what you feel
when the sun has warmed the road
and makes it impossible to walk
barefoot in the summer. The
sunlight reaches the road and the
energy is absorbed. Radiant energy
is how we keep food warm with heat
lamps.
• Image:
https://www.appropedia.org/images
/f/f3/Solar_radiation.jpg

16. Convection of heatImage left: http://www.photos-public-domain.com/wp-content/uploads/2011/11/bright-sun.jpg
Image right: https://farm5.static.flickr.com/4098/4778005211_715b12ac3b.jpg
• Once the sun’s rays reach the earth’s surface, the air
immediately above the ground warms. This process is
called convection.
• The warmed air begins to rise to higher altitudes.
This movement of warm air is called convection.