GLY1073 — Simple Energy Balance Model

1.) Develop a simple model of the Earth's energy system according to the instructions provided in the handout "Building Working Models: The Earth Energy System". What is the equilibrium temperature of the model? Why is this cooler than the observed global mean temperature of 15 degrees Celsius (288 degrees Kelvin)? Describe how the fact that outgoing energy is dependent upon earth's temperature (to the 4th power) acts as a negative feedback loop (hint: see p. 30 of handout).

2.) Change the depth of the swamp ocean to 10 meters. How long does it take the temperature to reach steady state? How does this compare to a swamp ocean depth of 0.5 meters? Why does it take longer to reach an equilibrium temperature with a deeper ocean?

3.) Find the sensitivity of the temperature to a 0.1% (1377 W/mw), 1% (1390 W/m2) and 10% (1514 W/m2) change in the solar constant. Express your answer as the difference in temperature from the control run (i.e., temperature derived in #1).

4.) Find the sensitivity of the temperature to a 1% (.303), 10% (.33), and 50% (0.45) change in albedo. Express your answer as the difference in temperature from the control run (i.e., temperature derived in #1).

5.) Change the solar constant to 2660 watts/m² and the albedo to a value of 71% to simulate the energy budget of the planet Venus. Assume that the size of the planets is the same. What is the predicted temperature of the planet? How does it compare to the measured temperature of 457 degrees Celsius (737 degrees Kelvin)? Why is the calculated temperature so different from the observed?