Experiment 3 - Glass Layers

In this experiment, you will observe what happens to the air temperature in a real greenhouse by placing virtual glass panes in the atmosphere.

Experiment procedure:

1. On the simulation screen, select Glass Layers
2. A simulation for an atmosphere with no greenhouse gases will automatically start running. Allow the simulation to run until the temperature settles roughly settles on a value (i.e., when the atmosphere reaches equilibrium). Note that the equilibrium temperature should be the same as the one recorded for no greenhouse gases in Experiment 1.
3. In the Options box, select the up arrow once (so that "1" is showing) to add one glass pane to the atmosphere.
4. As the simulation runs, document your observations of the number and paths of both solar radiation photons and infrared photons, and the change in air temperature. If needed, slow down the simulation in order to accurately observe the photons.
5. Once equilibrium is reached, record the equilibrium temperature of an atmosphere with no greenhouse gases and one glass pane.

After completing the experiment:

• In the submission template document, for Experiment 3, Observations and Data, enter your observations and data from steps 4 and 5 of the experiment.
• Based on your observations and data from the experiment, formulate a conclusion that generalizes the effect of the virtual glass pane on incoming and outgoing radiation, and on the equilibrium temperature of the atmosphere. Then, discuss why the term greenhouse* is used to describe the effect of atmospheric gases like carbon dioxide, methane, and water vapor on atmospheric temperature. Enter your conclusion and discussion in the submission template document, under Experiment 3, Conclusions.

*If you are not entirely sure of the meaning of the term greenhouse, research the topic before formulating your discussion.

Source : PhET Simulation (colorado.edu)f