T.O.C: Atmosphere Unit
Atmosphere -w.w- the whole layer of air
that surrounds Earth & supports & protects
• The earth’s atmosphere extends about
6000 miles. Even so, it is still incredibly
thin. • Atmospheric gases have
different characteristics at
different heights.
• Each layer puts pressure on the
one below creating
atmospheric pressure w.w. due
“Boyling” (air
to gravity pulling air molecules
towards Earth’s surface.
For this reason, scientists divided the atmosphere into
layers. These layers act like blankets that both support &
protect life on Earth. We will learn about the layers in a bit.
Characteristics & Materials of the Atmosphere
• Altitude w.w- distance above sea level. As altitude rises, the air becomes thinner
& harder to breathe.
• Density w.w- amount of mass in the given volume of a substance. If 2 objects
take up the same amount of space, then the object w/ more mass has a greater
density than the one w/ less mass. Ex: bowling ball & volley ball. DEMO~ Diet v
Regular soda
• Density of Earth’s atmosphere decreases w/ greater altitude. 99% of our
atmosphere is in the lower 20 miles…
DEMO~ Magnets on pencil
Most materials in the atmosphere are gases.
• Also contains tiny particles of solid & liquid material (such as salt, dust, & water
• In dry air, 78% of gas is Nitrogen, 21% is Oxygen, Carbon & others make up the
last 1%. Nitrogen, Oxygen & Carbon are extremely important for plants in
• The atmosphere’s gases provide materials essential for living things.
Natural Processes Modify the Atmosphere
The exact amount of gas in the air changes depending on location,
time, season, & other factors. Gases & water vapor are affected by
ongoing processes & sudden change
Ongoing Processes:
• You & all other living things participate in repeated & ongoing
processes of gas exchange w/in the atmosphere (as well as liquids
& solids. Ex: You breathe in about 3,000 gallons of air each day.)
• Cycles w.w- processes that repeat over & over.
3 Important Cycles that Affect the Atmosphere:
1. Carbon Cycle- CO2 & O2 constantly circulate among plants,
animals, & atmosphere.
2. Nitrogen Cycle- Different forms of Nitrogen cycle among
atmosphere, soil, living organisms. N enters soil after converted
out of air, then re-enters atmosphere from soil.
3. Water Cycle- Different forms of H2O cycle between Earth’s
surface & the atmosphere.
Sudden Changes
In addition to the ongoing cycles, dramatic events can cause changes
in the atmosphere.
When sudden events occur, it takes time before the atmosphere is
able to restore itself.
• Volcanic eruptions- volcanoes shoot gases & huge amounts of ash
into the atmosphere. Certain gases cause a haze that may affect the
air for months & lower temperatures.
• Forest fires- as forests burn, carbon that makes up each tree
combines w/ O2 & enters the atmosphere as CO2, & wood ash.
• Dust storms- wind, water, or drought can loosen soil. Powerful
windstorms may then raise clouds of this eroded soil. These storms
add huge amounts of particles to the air for the time.
The Sun supplies the Atmosphere’s Energy
Almost all the energy around you comes from the Sun. Food energy,
fires, & the warmth of your own body can be traced back to the Sun.
2 things happen to sunlight that reaches Earth.
~ Some is reflected/sent in a new direction
~ Some is absorbed (which heats the object that absorbs it.
Radiation-w.w- energy that travels across distances as certain types of
waves. Visible light and other types of radiation can be absorbed or
30% of solar radiation is reflected.
70% is absorbed by oceans, landforms, &
living things & heats Earth’s surface
DEMO- Cup/water/temp. pg. 17
The Atmosphere moves Energy
Radiation, conduction, & convection are processes that move energy
from place to place.
~Radiation: solar radiation from Sun heats warms surfaces, but the
Earth’s surface also gives off infrared radiation which heats gases in the
~Conduction: w.w- transfer of heat energy from one object to
another by direct contact. Think of walking barefoot on asphalt.
Earth’s surface transfers energy to the atmosphere, such as when hot
beach sand warms the atmosphere above it. This can happen both
quickly & slowly.
~Convection: w.w- transfer of energy from place to place by motion
of gas or liquid. Differences in density produce motion of air
These three processes helped to create the atmosphere’s layers &
*Scientists use the patterns of temperature change to determine the 4
layers of the atmosphere.
Layers of the Atmosphere
(create atmospheric heat illustration)
Troposphere.w.w- The 1st
layer closest to the earth
The Troposphere is 4 to 12
miles thick.
Almost all of the Earth’s
weather takes place here.
It contains almost all of the
Earth’s water vapor.
It extends about as high as
birds can fly.
4 – 12 miles (6 – 20 km) above Earth
Warmed by the ground
below, so is warmest @
ground level & cooler the
higher you go
Stratosphere-w.w- The
atmosphere’s 2nd layer
The Stratosphere is a clear/dry
layer that has little moisture
and no clouds, but it does
have winds.
Planes fly here.
The Stratosphere stretches 30
miles above the planet.
12 - 31 miles (20 – 50 km) above Earth
Ozone gas is found here.
These molecules absorb solar
radiation that is harmful to
The energy from this
radiation raises the
temperature in the air & gets
higher as you rise thru the
The Mesosphere-w.w- is the
third layer of the atmosphere.
The name of the layer
means “middle layer”.
The air in the Mesosphere
is extremely thin, but
protects the Earth from
meteors; it burns them up
as they enter.
It’s too high for planes and
weather balloons, too low
for satellites, making it
hard to study.
31 – 53 miles (50 – 85 km) above Earth
The Mesosphere is also
heated from below (like 1st
layer) so temperature falls
as you rise thru it.
Thermosphere-w.w- The fourth
layer. Has 2 parts 1) Ionosphereinner part of the thermosphere
where the Sun’s radiation is so
strong it breaks apart molecules!
& the 2) Exosphere- next pg.
53 – 375 miles (85 – 600 km) above Earth
This is the largest of all the
atmosphere’s layers.
The international space
station orbits here.
The temperature gets very
high here and protects us
from the harsh cold of
outer space by absorbing
the 1st round of solar
radiation. Temperature
increases as you rise thru it.
However, the
layer/molecules are so big
& spread out, you wouldn’t
feel the heat on your skin.
Exosphere-w.w- Beyond
these four layers. Outermost
part of the Thermosphere &
all of outer space lies
Scientists have learned about
the Exosphere from satellites.
It is the planet’s first line of
defense from meteors,
asteroids and cosmic rays.
It is the boundary area
between outer space and our
atmosphere (the
375 – 6,200 miles (600 –10,000 km) above Earth
Magnetosphere-w.w- the area
around the earth that extends
beyond the atmosphere
The earth's magnetic field
operates here. It begins at
about 1000 km. It is made
up of positively charged
protons and negatively
charged electrons.
This traps the particles that
are given off by the sun. They
are concentrated into belts,
or layers, called the Van Allen
radiation belts.
The Van Allen belts trap
deadly radiation.
Causes the aurora borealis.
Begins about 621 miles (1,000 km +) above Earth
Review Q’s – 24 points
What substances make up air? 2 pts
Which is the most abundant gas in the atmosphere? 2 pts
Draw a diagram showing how 1 of the 3 natural cycles affects the
atmosphere. 5 pts
How would the atmosphere in your area change if all the plants
died? 2 pts
What 2 things happen to the sunlight that reaches Earth? 2 pts
Describe the 3 processes that transport energy. 6 pts
What characteristic do scientists use to define the 4 main layers
of the atmosphere? 2 pts
Jet planes fly near the top of the troposphere. Would it be more
important to heat or to cool the passenger cabin? Explain your
reasoning. 3 pts
T.O.C~ The Ozone Layer
Notes Heading:
The Ozone Layer
Protects Life
… (Yay!.. Except for this big hole… Boo!..)
Atmosphere History/Ozone wkst
The Ozone Layer Protects Life
 Remember: the atmosphere reflects/absorbs sunlight which is
made of all types of the EMR spectrum.
 This means not all EMR is getting thru b/c of certain gases in
the atmosphere.
 Ultraviolet (UV) radiation-w.w- has more energy (tighter
waves) than visible light, causes sunburns & other damage
 Infrared radiation-w.w-have less energy (looser waves) than
visible light, usually warms the materials that absorb it
 Ozone-w.w- made of 3 atoms of Oxygen (O3). In the
stratosphere ozone & regular Oxygen (O2 –what we use)
break apart & form again in a complex cycle. This is called the
Ozone Layer – however there are still other gases here (N)
The Ozone Layer Protects Life
 You ask: so how does it protect us?
 The ozone layer protects life on Earth by absorbing
harmful/hot ultraviolet (UV) radiation & letting other
types of radiation thru- visible light!
 Too much could give you: sunburn, skin cancer, &
harm eyes
 Can also harm crops & materials like plastic & paint
 Types of UV radiation:
UVA- Age us- goes into dermis- the skins thickest layer, can
cause wrinkles, age spots, cancer. UVB- burn us- top layers of
the skin- very painful, can cause permanent damage
The Ozone Layer Protects Life
The Ozone Layer Hole
 Over Antarctica. Hole = no protection from UVB rays = bad 
 The discovery of the Ozone Hole was first announced in a paper by British
Antarctic Survey’s Joe Farman, Brian Gardiner and Jonathan Shanklin
(pictured at top), which appeared in the journal Nature in May 1985.
Antarctica (South Pole) ozone layer is vulnerable to chemicals & other
pollutants in the atmosphere due to its cold temperatures & the amount
of sunshine it receives.
Major volcanic eruptions, such as the 1991 eruption of Mount Pinatubo in
the Philippines may put material which enhances ozone depletion into the
Scientists working in Antarctica wear high-factor sunscreen to avoid
sunburn when working outside, especially as sunlight is also reflected from
the snow surface. You can get burnt in as little as five minutes without it
The Greenhouse Effect v. Global Warming
 2 different concepts that contribute to one another.
 Greenhouse Effect-w.w- certain gases slow the mvmt of energy away from the
Earth’s surface. The gases absorb & emit infrared radiation which helps trap heat.
(like glass in a window/greenhouse)
 Greenhouse Gases (GHG)-w.w- CO2, Methane, water vapor (H2O), Nitrous
oxide, & other gases that absorb & give off infrared radiation. Do not form in
layers- they are all mixed together, the atmosphere is thickest in troposphere b/c
that’s where all these gases are. Most occur naturally. However, human activity
causes them to produce much faster. Farming (chemicals)/cars/factories
 Global Warming-w.w- when the average temperature of the Earth’s atmosphere
and the oceans rise. The temperature of the Earth is on a constant rise since the
beginning of time, but recent warming conditions have been drastically
increasing the rate of the temperature on Earth.
 The increase in human activities as well as human population has shown an
increase in the amount of emissions that are produced world-wide. A surge in use
of cars, fridges, planes, etc. has resulted in rise of emissions which are directly
responsible for global warming which has increased drastically since 1980’s
 Key Difference: Global warming is when the average temperature of the Earth’s
atmosphere and the oceans rise. Greenhouse effect is the retention of the heat by
the greenhouses gases on the surface of the Earth, allowing the planet’s
temperature to rise allowing water not to freeze, etc.
T.O.C ~ The Human Impact (also notes heading)
Humans affect the Atmosphere
 Human activity causes air pollution: cars, factory, coal (C)
 Chlorofluorocarbons (CFC)- chlorine & other harmful gases emitted into air
which begin breaking down ozone (O3). 85% of chlorine in atmosphere is put
there by humans. Used in A/C, aerosol/spray cans, packaging foam
Air pollution-w.w- smoke from burning/ factory emissions & other harmful
materials that are added to the air.
Pollutants-w.w- different types of air pollution. Includes ozone, methane, sulfur
oxide, nitrogen oxide, carbon monoxide
2 Types of Pollution
Gases – carbon dioxide, oxygen, methane, carbon monoxide
Particles- dust/dirt, pollen, sand, salt.
 Particulates-w.w- tiny droplets mixed with air
Fossil fuels-w.w- fuels formed from remains of prehistoric plants & animals.
Burning coal provided heat/energy but also thick fog/cloud
Smog-w.w- combination of smoke and fog
 ppl who breathe polluted can develop lung disease & other health issues
 Can be carried into upper atmosphere (affect weather), move from sky to
ground through rain
Ways we Can Help
 Use clean air producing technology
 Reduce GHGs by biking/driving hybrids
 Use more clean energy in day to day life
 Try to find a substitute material for CFCs. Less used now since Montreal
Protocol in which 180 nations agreed to stop making/using these CFCs.
If all countries would follow we could return to normal relatively soon
Review Q’s 30 pts
Give 2 sources of air pollution (2 pts)
Name 2 human activities that affect greenhouse gases? (2 pts)
What is the key difference between greenhouse effect & global
warming? (4 pts)
What is ozone? How do human activities affect the ozone layer?
(3 pts)
Why is Antarctica vulnerable to ozone layer loss? (2 pts)
Describe 3 ways life & the atmosphere affect one another. (6 pts)
What are the 2 types of pollutants? Give an example of each. (4
What type of radiation does the ozone layer affect? ( 2 pts)
How do greenhouse gases keep Earth warm? (2 pts)
How does the ozone layer protect life on Earth? (3 pts)