PURPOSE:This activity allows you to compare two Eocene climate simulations with that of a modern simulation. You will identify key differences between the Eocene simulations, and between the Eocene and modern and develop hypotheses to explain these differences. You will also consider the general accuracy of these simulations in the context of what you already know about Eocene climate from proxy data.

EXPERIMENTS:
You will compare results from high and low CO2 Eocene experiments with modern climate. All simulations were run with the same climate model, the NCAR Community Climate System Model. This is a global climate model with individual components for the atmosphere, oceans, land, and sea ice. Vegetation is prescribed – meaning that the plants specified in the boundary conditions do not respond to changes in climate. Plants do, however, exchange energy and moisture with the atmosphere, as part of the land surface. The Eocene experiments utilize Eocene geography.

ANALYZE EOCENE DATA :
Proceed to the Model Output Plots page. Using the data you can access here, jot down some notes regarding the following on a sheet of paper:

Under the first option, click on the 'map-view' and 'cross-section' plots to examine the Modern, Low, and High CO2 Eocene experiments.

QUESTIONS:

Do you find any general correlations between temperature and regions of greatest precipitation?
Record general differences between ‘low CO2’ and ‘high CO2’ climate during the Eocene, as depicted in temperature, precipitation, and cloud cover output.
Identify general differences between Eocene and Modern climate, as depicted in temperature, precipitation, and cloud cover output.
Identify locations where climate is most sensitive to CO2.
Identify levels in the atmosphere where temperature and cloud are most sensitive to CO2.

HOMEWORK:

The homework questions are provided on the handout. Use your notes to assist you in answering the homework questions. When you have completed this part of the activity, proceed to the Eocene Tilt Experiments (second option on the Model Output Plots page), and follow the directions on the activity handout.