Do Now – 5 Minutes
Topic – The Atmosphere - Layers
• You will all be following along with today’s
notes with fill-in notes.
• After notes, you’ll have time to finish your
poster projects.
• At the top of your notes, I would like you
to recall and list the layers of the
atmosphere.
Homework
Complete the Carbon Cycle worksheet
(Two Days Late).
Upcoming Quiz
On Wednesday, we will have a short
quiz.
Quiz is on the Hydrosphere, Biosphere,
and small amount of Atmosphere.
We will review in class on Tuesday,
11/25.
Atmosphere
The last, and outermost portion of Earth’s
spheres is the atmosphere.
Atmosphere
Earth’s atmosphere serves as a
protective boundary for all life forms on
the planet.
Not all planets have suitable
atmospheres for organisms.
What’s wrong with the atmosphere on
Venus?
What’s wrong with the atmosphere on
Mars?
Atmosphere of Venus
Venus’s atmosphere is WAY too thick and
traps in heat.
Atmosphere of Mars
Mars’s atmosphere is too thin to keep the
planet a regular temperature and protect
it from space junk.
Creation of our Atmosphere
How did our atmosphere form?
Earth’s first atmosphere was made of
helium and hydrogen.
This helium and hydrogen escaped
though, since they’re so light.
Creation of our Atmosphere
Earth’s second atmosphere was formed
through volcanic eruptions.
Volcanos released H2O, CO2, and
ammonia (NH3).
Creation of our Atmosphere
Earth’s third and current atmosphere was
a result of plants and animals.
Most CO2 dissolved into the ocean.
Bacteria converted sunlight + CO2 into O2
Sunlight broke apart NH3, leaving H to
escape.
Atmosphere of Earth
There are five layers of Earth’s
atmosphere:
Atmosphere of Earth
Use a pneumonic to help yourself
remember the order of the layers:
tra
Exosphere
ermals
Thermosphere
Mesosphere
an
Stratosphere
inky
iceps
Troposphere
Troposphere
Contains 3/4 of the atmosphere’s mass,
but it is very thin!
Goes from the surface of the Earth, to
7 miles up (11 km).
Almost all of the clouds we see are in the
troposphere.
The movement of the troposphere is
responsible for weather!
Troposphere
The higher up you go in the troposphere,
the colder it is (Temp at top: -70.6 ºF)
At the top, it stops getting colder.
Stratosphere
Extends from 7 – 31 miles (11 – 50 km)
up from the surface.
The gases in the stratosphere do not mix
very well – meaning if pollution reaches
the stratosphere, it stays there.
As you ascend the stratosphere, it gets
warmer. (Temp at top: 26.6 ºF)
Warmest temperatures are at the top of
the stratosphere.
Stratosphere
Planes fly in the stratosphere
Stratosphere
The Ozone layer (O3) is in the stratosphere as
well.
The upper layer of the stratosphere is the
warmest due to UV rays from the sun
absorbing and scattering at the top.
The deeper you go
down, the UV rays do
not penetrate as deep.
Stratosphere
If we did not have the ozone layer, there
would not be life on Earth.
Mesosphere
Extends 31 – 50 miles (50 – 80 km)
above the surface of the earth.
As you ascend in the Mesosphere,
temperature decreases.
Temperatures reach as low as -226ºF
Cold temperatures are due to seasonal
changes, less solar heating, and CO2
cooling.
Mesosphere
Meteors burn up meteors when they
approach Earth.
This is why Earth is not covered in
craters like other planets.
Mesosphere
Here’s a video of the Mesosphere in
action. Link
This is the least-researched layer of the
atmosphere.
It’s too high for planes to reach, but too
low for orbital spacecraft to navigate.
Thermosphere
Last official layer of the atmosphere.
The air is INCREDIBLY thin here.
Thermosphere extends 50 miles above
the surface of the Earth and beyond.
The temperature here is very high
(3,630 ºF) due to solar activity.
Thermosphere
Since the air is so thin, and there are so
few gas molecules, you would actually
not feel that heat.
Molecules of air are so far away from
each other, sound does not transmit
either.
Thermosphere
The International Space Station
maintains its orbit in the thermosphere
Thermosphere
Aurorae borealis occur in the
thermosphere as well
Exosphere
The last “layer”.
This is where the atmosphere ends and
merges with space.
Sometimes it is just considered part of
outer space.
It is mostly made up of hydrogen, helium,
CO2, and atomic oxygen.