Walker Lab 12
.docx
keyboard_arrow_up
School
Arapahoe Community College *
*We aren’t endorsed by this school
Course
101
Subject
Astronomy
Date
Dec 6, 2023
Type
docx
Pages
6
Uploaded by UltraArtLemur17
Arapahoe Community College
Astronomy 1110
Lab 12
A
STRONOMY
1110
L
AB
12: G
REENHOUSE
E
FFECT
Procedure
1.
You will be using the PhET Simulation
The Greenhouse Effect.
This simulation
may take a minute or two to open, so please be patient. After it opens, click the
play button to start the simulation. Run the Simulation in the Greenhouse Effect
Tab, keep all the default settings. Then vary each of the settings to see how this
changes the system. Give the simulation time to settle after you make a change.
Page 1
Arapahoe Community College
Astronomy 1110
Lab 12
A.
What do the yellow dots that move downward in the simulation represent?
The yellow dots in the simulation represent sunlight photons.
B.
What do the red dots in the simulation represent? Do all the red dots all
move upwards? Why or why not?
The red dots represent infrared photons and not all of the red dots move
upwards. Some are trapped in by the clouds and some are trapped in by
green house gases.
Page 2
Arapahoe Community College
Astronomy 1110
Lab 12
C.
Reset the sim and select “1750” and let the temperature rise to equilibrium
(about 2 minutes). How did the temperatures during the 1750’s differ from
today?
What was different about the atmospheric composition that could
cause this?
The temperatures during the 1750s were about 5 degrees cooler than the
temperatures today. There was a smaller presence methane, carbon dioxide
and nitrous oxide than compared to today.
D.
Reset the sim and select “ice age” and let the temperature rise to
equilibrium. How did the temperatures during the Ice Age differ from today?
What was different about the atmospheric composition that could cause
this?
The temperatures during the Ice Age were almost 30 degrees cooler than
today. The temperatures were ranging between 30-40 degrees F. The largest
changes in the atmosphere is there is about 200 less ppm of carbon dioxide
than today. There was 1.5ppm less of methane and .1ppm less nitrous oxide
than today.
E.
Now add a few clouds. What is the role of clouds in the planet’s
temperature? Think about clouds in your everyday life as well, both during
the day and at night.
Clouds block photons of infrared and sunlight. These clouds keep the
temperature of the planet cooler.
2.
Run the Simulation in the Photon Absorption Tab, keep all the default settings.
Then vary each of the settings to see how this changes the system. Give the
simulation time to settle after you make a change.
A.
Do all the photons pass through a methane molecule? Explain.
Not all infrared photons pass through a methane molecule. The methane
molecule traps and diverts the path of some of the infrared photons.
B.
When a photon gets absorbed, what happens to the methane molecule
next?
The methane molecule shakes and creates a new photon.
C.
When a new photon is emitted from the methane molecule, is it always sent
in the same direction?
The new photon is typically not sent in the same direction it is sent in a
random direction.
D.
Which molecules absorb visible light? What molecules absorb infrared light?
Page 3
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
- Access to all documents
- Unlimited textbook solutions
- 24/7 expert homework help