Experiment 2 - The Effect of Clouds on Atmospheric Temperature

In this experiment, you will investigate how the presence of clouds affects atmospheric temperature.

Experiment procedure:

1. Repeat steps 1-3 and 5 of Experiment 1. (Note that the equilibrium temperature should be the same as the one recorded for no greenhouse gases in Experiment 1).
2. In the Options box next to Number of Clouds, select the up arrow three times (so that "3" is showing) to add three clouds to the atmosphere.
3. As the simulation runs, document your observations of the paths and number 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.
4. Once equilibrium is reached, record the equilibrium temperature of an atmosphere with no greenhouse gases and with clouds.

After completing the experiment:

• In the submission template document, for Experiment 2, Observations and Data, enter your observations and data from steps 3 and 4 of the experiment.
• Based on your observations and data from the experiment, formulate a conclusion that generalizes the effect of clouds on incoming and outgoing radiation, and on the equilibrium temperature of the atmosphere. Enter your conclusion in the submission template document, under Experiment 2, Conclusions.

PhET Simulation (colorado.edu)