Name ______________________________ J#________
The layers of our atmosphere
BACKGROUND:
A blanket of air, which we call the atmosphere, surrounds the Earth. It reaches over 560 kilometers (348
miles) from the surface of the Earth.
The atmosphere, solar energy, and our planet’s magnetic fields support life on Earth. It has many functions,
it:
 absorbs the energy from the Sun
 recycles water and other chemicals
 works with the electrical and magnetic forces to provide a moderate climate
 protects us from high-energy radiation and the frigid vacuum of space
The atmosphere is composed of 78% Nitrogen, 21% Oxygen, 1% other gasses (such as Argon, Ozone,
Water, and Carbon Dioxide). These gasses are broken up and distributed among the 5 sections of the Earth’s
atmosphere: The Troposphere, Stratosphere, Mesosphere, Thermosphere, and Exosphere. The upper
boundaries between these layers are known as the tropopause, the stratopause, and the mesopause,
respectively.
Temperature variations are what divide the five layers. These variations
are due to the way the solar energy is absorbed as it moves downward
through the atmosphere. The Earth’s surface is the primary absorber of
solar energy (radiation). Some of this energy is reradiated by the Earth
as heat (through convection (transfer through gasses or liquids) or
conduction (transfer from a liquid/gas to solid or vice versa), which
warms the overlying troposphere. The global average temperature in the
troposphere rapidly decreases with altitude until the tropopause, the
boundary between the troposphere and the stratosphere.
The temperature begins to increase with altitude in the stratosphere. This warming is caused by a form of
oxygen called ozone (O3) absorbing ultraviolet radiation from the sun. Ozone protects us from most of the
sun’s ultraviolet radiation, which can cause cancer, genetic mutations, and sunburn. Scientists are concerned
that human activity is contributing to a decrease in stratospheric ozone. Nitric oxide, which is the exhaust of
high- flying jets, and chlorofluorocarbons (CFCs), which are used as refrigerants, may contribute to ozone
depletion. At the stratopause, the temperature stops increasing with altitude.
The overlying mesosphere does not absorb solar radiation, so the temperature decreases with altitude. At the
mesopause, the temperature begins to increase with altitude, and this trend continues in the thermosphere.
Here solar radiation first hits the Earth’s atmosphere and heats it. Because the atmosphere is so thin, a
thermometer cannot measure the temperature accurately and special instruments are needed.
Name ______________________________ J#________
Name ______________________________ J#________
Exosphere



Furthest layer from Earth (400 KM and beyond or 248. Miles and beyond)
Very few gasses here, and those dissipate into space
This is where the atmosphere merges with space.
Thermosphere
 80-400 KM from Earth (49.7-248.5 miles)
 This is the thickest layer by far
 High temperatures (up to 3600 degrees Fahrenheit) because the atoms absorb the energy from the sun.
 Satellites, the Space Shuttle, and the International Space Station orbit here (at the top)
 Auroras, or colorful nightly displays due to the mixture of gasses, occur here—Result of magnetic storms!
 Contains the ionosphere: Before the modern use of satellites the ionosphere was essential for long distance
radio communication—reflects radio waves back to Earth. Sun's energy is so strong at this level, that it
breaks apart molecules. So there ends up being electrons floating around and molecules which have lost or
gained electrons. When the Sun is active (producing solar flares), more and more ionization happens.
 The sun’s X-rays and UV rays are absorbed by the thermosphere.
Mesopause---------79.1 Km – 79.9 Km
Mesosphere
 50 – 79 KM from Earth (31.1 – 49.0 miles)
 Coldest layer of the atmosphere (–130 degrees Fahrenheit)
 Meteors burn up in this layer
Stratopause-------- 48.1 Km – 49.9 Km
Stratosphere
 18 – 48 KM from Earth (11.2 – 29.8 miles)
 This is “The Ozone layer.” It contains the most ozone particles of any layer. On Earth’s surface, Ozone
would be extremely, but in the atmosphere it is our protective layer.
 Absorbs harmful UV rays from the sun that could cause skin cancer and destroy vegetation.
 UV rays get “trapped” at the border of the Stratosphere and Mesosphere so it is hottest at that border.
 Large Commercial Airplanes, Sonic Airplanes such as the Concorde, and spy planes fly in this layer.
Tropopause -------- 12.1 Km – 17.9 Km

AKA the "cold trap"
(where rising water vapor cannot go higher because it changes into ice and is trapped)
–Without it we would lose our water!
Troposphere
 Earth’s surface – (approx) 12 KM (7.5 Miles)
 This is where all weather occurs.
 The heat source in this layer is the Earth’s surface itself b/c the surface of the Earth absorbs energy and heats
up faster than the air does.
 Temperature decreases as up move away from the Earth… Think: Mountains!
 Many Commercial airplanes travel at the top of this layer
 99% of the Earth’s “AIR” is in the Troposphere and Stratosphere.
 Only layer containing LIFE!!!
Earth’s surface
Model of the Earth’s Atmosphere Layers Lab
Name ______________________________ J#________
You and a partner are going to create a model of the Earth and its layers of the atmosphere. This will allow
you to better understand its characteristics and components of each layer.
Materials:
2 Meters of adding machine paper.
Ruler
Calculator
Compass
Colored pencils, markers, and a pencil
Procedure:
1. Using the following scale figure out the cm equivalents -- (_____km x2) / 10
Troposphere = Earth’s surface to 12 km
____0___ cm to __2.4___cm (12x 2) / 10 = 2.4
Tropopause = 12.1 km to 17.9 km FROM EARTH
________ cm to _________ cm
Stratosphere = 18 km to 48 km FROM EARTH
________ cm to _________ cm
Stratopause = 48.1 km – 49.9 km FROM EARTH
________ cm to _________ cm
Mesosphere = 50 km to 79 km FROM EARTH
________ cm to _________ cm
Mesopause= 79.1 km – 79.9 km FROM EARTH
________ cm to _________ cm
Thermosphere = 80 km to 400 km FROM EARTH
________ cm to _________ cm
Exosphere = 400 km FROM EARTH and beyond
________ cm to
end of paper
2. Find center of the adding machine paper. Draw a circle with a diameter of 4 cm. (Set your compass at
2cm.) This is the Earth’s core, mantle, and crust (It isn’t really a sphere, as the atmosphere is what makes
our planet a sphere….we are drawing the core, mantle, and crust as a sphere for modeling purposes.
3. On both sides of the Earth that you drew, measure the distances above in order to label each layer of the
atmosphere (and the pauses).
4. Differentiate between the layers by labeling and drawing distinguishing characteristics using markers,
colored pencils etc. MAKE SURE YOU INCLUDE TEMPERATURE (COLD TO HOT and vice
versa).
Rubric --Correct scale calculations (above)
Correct measurements
Defining characteristics marked and labeled
Neatness
Creativity/Originality
______/5
______/20
______/20
______/20
______/5
Total Points Possible
______/70