Glass Layers

Part 1: Glass Layers (Greenhouse)

Click on the “Glass Layers” tab at the top of the screen of the Greenhouse Effect Simulation.

Introduction: Global warming is perhaps the “hottest” topic in today’s headlines. The cause of warming is usually blamed on the “greenhouse effect” or “greenhouse gases.” The following simulation will allow you to first examine how the “greenhouse effect” works in a greenhouse. You will then experiment with a simulation of the earth’s atmosphere where the concentration of greenhouse gases can be varied. Finally, you will use the results of the two simulations to describe how the “greenhouse effect” affects temperature on the earth.

Hypothesis: Write what happens to make the inside of a car feels so much warmer than its surroundings on sunny days.

I think that, since there is not much air circulation inside of a car when it is not turned on, the sunlight becomes trapped, therefore making the inside of the car very warm.

2a. What do the yellow dots moving down represent?

Sunlight photons

2b. What do the red dots represent?

Infrared light

2c. Record the approximate temperature “inside the greenhouse” before adding glass panes:

2 Fahrenheit

Prediction: Make a prediction about what will happen when you add a glass pane:

I think that the sunlight photons (yellow dots) will be able to pass through

Test your prediction: add one glass pane.

2d. What do the sunlight photons do when they hit the glass from the top? Do they all do the same thing?

The sunlight photons pass through. They all do the same thing.

2e. What do the infrared photons do when they hit the glass from the bottom? Do they all do the same thing? Be specific.

The infrared photons either pass through or shoot back toward earth.

2f. What is the new temperature “inside the greenhouse?”

80 Fahrenheit

2g. Based on the observations of the photons, why does the temperature change?

The temperature changes because more sunlight photons are passing through.

Now add one more glass pane and watch. Then add the third glass pane.

2h. What happens to the temperature as additional glass panes are added?

The temperature inside increases.

2i. Explain why this happens by observing the photons.

The added pane is able to trap in the photons that passed through the first glass pane.

2k. Before proceeding to the earth, predict how what you have discovered regarding greenhouses might apply to the earth and its atmosphere.

The greenhouse gases that surround us in the atmosphere act very similarly to the glass panes shown in the simulation, because they are both able to capture and trap heat.

Part 2: The Earth’s Atmosphere

Click on the “Greenhouse Effect” tab at the top.

3a. What do the yellow dots moving down represent?

Sunlight photons

3b. What do the red dots represent?

Infrared photons

3c. Watch the red dots carefully. Do they all move upwards? Why or why not?

No, some of them move back down because they are being trapped by the greenhouse gases.

3d. Is the behavior of the photons more similar to the greenhouse simulation with or without glass panes?

It is more similar to the simulation with glass panes.

3e. Which time period do the default conditions represent?

They represent the conditions of todays.

With the Atmosphere set to “Today,” fill out the table below: