Atmosphere Lesson

Vers. 08/2020 © Kesler Science, LLC

Atmosphere

Presented by Kesler Science

© Kesler Science, LLC

Atmosphere

Essential Questions:

Reflect on the Essential
Questions before you dive in…

1. If you were quizzed today,
which questions would you know
the answers to already?

2. Which questions would you
need to learn more about to
answer confidently?

1.

What is the
composition of the
Earth’s atmosphere?

2.

What are the layers
of the Earth’s
atmosphere?

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Atmosphere

Atmosphere

Layer of gases that surround
the earth. Its purpose is to:
•Support life on Earth by
protecting it from
dangerous
electromagnetic radiation

•Create and control
weather and climate

•Provide gases plants and
animals need to breathe

What is the
atmosphere?

Multiple Choice

Which of the following is not a role of the atmosphere

• protection

• pollution

• weather and climate

• gases for breathing

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Atmosphere
Composition of
the Atmosphere

• 78% nitrogen
• 21% oxygen

• 0.90% argon
• 0.03% carbon dioxide

(CO2)

• 0.17% other trace

gases (neon, methane,
krypton, hydrogen)

Make 2 observations about

the composition of the

atmosphere.

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Atmosphere

Gases important to life on Earth

Multiple Choice

Which of the following gases vary in the atmosphere?

• nitrogen

• oxygen

• water vapor

• carbon dioxide

Multiple Choice

Which of the following gases in important for plant growth

• nitrogen

• oxygen

• water vapor

• carbon dioxide

Match

Match the following

• oxygen

• carbon dioxide

• nitrogen

released by plants

removed by plants

used by plants for growth

• released by plants

• removed by plants

• used by plants for growth

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Atmosphere Atmospheric Pressure
Pressure

• Pressure exerted on

Earth by atmosphere

• Decreases with increased

altitude

• 14.7 pounds per square

inch at sea level

Does the thermosphere or troposphere

have the greatest atmospheric

pressure?

90 km

50 km

350 km

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A Atmosphere
Atmospheric
Density

• At greater altitudes the

same volume contains
fewer molecules of
gases

• Measured with a

barometer

Compare the volume of molecules

at Earth’s surface and far above

Earth’s surface.

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Atmosphere

Atmospheric Warming

Solar radiation
• 49% absorbed by earth’s surface
• 20% reflected back by clouds
• 20% absorbed by atmosphere and clouds
• 6% scattered by atmosphere
• 5% reflected by earth’s surface

What percentage of the solar radiation reaches Earth’s surface?

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Layers of the
Atmosphere

• Troposphere
• Stratosphere
• Mesosphere
• Thermosphere
• Exosphere

The ozone layer is between what

two layers of the atmosphere?

Reorder

Reorder the following

• troposphere

• stratosphere

• mesosphere

• thermosphere

• exosphere

1

2

3

4

5

• 1
• 2
• 3
• 4
• 5

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Layer Boundaries

• Differences in

temperatures separate
each layer from next.
Follow the red line to see
the temperature in each
layer

• Temperature remains

constant through boundary

• Boundaries:

•Tropopause
•Stratopause
•Mesopause

Layer

Boundaries

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Atmosphere

Troposphere

• Lowest layer

• Most atmospheric air is found here.

• Extends from 0 -14Km (9mi.) above Earth

• Air temperature decreases with height above

Earth

• Virtually all weather occurs here

As you get higher in the troposphere,
what happens to the temperature?

Multiple Choice

Temperature in the Troposphere _____ as altitude increases.

• increases

• decreases

• is constant

Atmosphere

Weather in the Troposphere: Winds

Caused by unequal heating of the earth’s surface.

Land Breeze

Sea Breeze

Think About It

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One of the factors that affect breezes along
a shoreline is the temperature of the land
compared to the temperature of the water.

Look at the diagrams on the previous slide.

Predict what would happen to the breezes
as the seasons change throughout a year.

Multiple Choice

A land breeze would come from the _____.

• land to the sea

• sea to the land

• sky to the ground

Atmosphere

• Moisture moves through the water cycle;

surface water is heated by the Sun to
start evaporating, then it condenses and
precipitates (falls).

• Humidity – depends on amount of water

vapor in the air and air temperature

• Dew point – temperature at which water

begins to accumulate on surfaces
(condense)

Weather in the Troposphere: Moisture (water vapor)

What is the water cycle?

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Atmosphere

Weather in the Troposphere:
Clouds (Four main types)

Four Main Types of Clouds

Cirrus – high level, wispy, curly, composed
of ice crystals

Cumulus – mid level, fluffy, dense, mostly
composed of water droplets

Stratus – low level, layers like a blanket,
composed of water droplets

Nimbus – extend through all levels, rain,
storm

Match

Match the following

• cumulus

• stratus

• cirrus

• nimbus

mid-level, fluffy

low level, layers

high level, wispy, ice

rain, storm

• mid-level, fluffy

• low level, layers

• high level, wispy, ice

• rain, storm

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Atmosphere

Stratosphere

• Air temperature increases with height above earth

due to ozone (O3) absorption of sunlight

• 14km to 50km above earth
• Very calm layer allows for undisturbed flight
• Ozone layer found near the bottom of stratosphere

As you get higher in the stratosphere, what happens to the temperature?

Weather
balloons

Supersonic Jets

Think About It

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Convection currents are vertical movements in bodies of air and liquids. In the
troposphere, heat at Earth’s surface warms the nearby air, causing its molecules to spread
apart and rise. As it rises, it cools, becoming more dense again and sinking back down.
These convection currents create turbulence and weather patterns in the troposphere.

The stratosphere has a steady wind, but practically no turbulence. Look back at the
temperatures of the stratosphere and predict why there is much less turbulence than in
the troposphere.

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Ozone Layer

• Ozone gas (O3) absorbs solar

radiation

• Releases it as heats
• Protects earth from harmful

UV rays

• Ozone can be “good” or “bad”

at different altitudes.

Compare good and bad ozone.

Multiple Choice

Ozone is a type of _____.

• nitrogen

• carbon

• oxygen

• water

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Atmosphere

Mesosphere

• 50km – 80km
• Air temp. decreases with height above Earth
• Coldest layer -100o C
• Protects Earth – meteoroids usually burn up in

this layer

As you get higher in the mesosphere, what happens to the temperature?

How does the mesosphere

protect Earth?

Open Ended

If the Mesosphere is the coldest layer, why do meteors burn up in it?

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Atmosphere

Thermosphere “heat sphere”

• 80km out into space
• Temp. increases with height above earth;

(1,800o C – 3,300o F )

• Aurora Borealis (Northern Lights)
• Space shuttle orbits here
• Ionosphere – the lower part
• Exosphere – the upper part

As you get higher in the thermosphere, what happens to the temperature?

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Atmosphere

• Particles become electrically charged (ions).
• Radio waves are bounced off the ions and reflect

back to Earth.

Ionosphere

• Included in Mesosphere

and Thermosphere

• 80km – 550km
• Gas particles absorb

ultraviolet and X-ray
radiation from the sun

How does the

ionosphere enable us to

listen to the radio?

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Atmosphere Exosphere

• 550km - thousands of km

into space

• Air is very thin

• GPS satellites orbit the

earth here

What causes the exosphere to have a

very low atmospheric density?

Think About It

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“Tropo” is a form of a Greek word that means turning, or
change. The troposphere is an area where the air is
constantly turning and changing, giving us our weather
conditions. Look at these other root words. How do they
relate to the parts of the atmosphere named with them?



strato-: spread-out, layers

• meso-: middle

• thermo-: heat, temperature

• exo-: outer, outside part

Match

Match the following

• tropo

• strato

• meso

• thermo

• exo

turning, change

spread out

middle

heat, temperature

outer

• turning, change

• spread out

• middle

• heat, temperature

• outer

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Beyond the
Atmosphere

Magnetosphere
• Earth’s magnetic field
• About 1000km above

Earth’s surface

• Traps harmful particles

from the sun

Where is the magnetosphere located?

• Particles concentrate into belts or layers called the

Van Allen radiation belts

• Causes the aurora borealis in the upper atmosphere

Magnetosphere squished by solar wind

Give your best answer to...

1.

What is the composition of the Earth’s atmosphere?

2.

What are the layers of the Earth’s atmosphere?

3.

Identify the 4 main cloud types?

Check for

Understanding

Still have
questions?

Which essential questions do you still need help to understand?