Paleo Documentation

Before you begin

If you are considering a Paleoclimate project using the CESM model you may find it useful to answer the following questions.  We strongly recommend that you complete the exercises in the CESM tutorial and run a short pre-industrial simulation of the CESM model before you start working on your paleoclimate simulation.  

  • What scientific question do you plan to investigate with the CESM?
  • The current release of the CESM may not resolve all the necessary processes nor have adequate resolution critical for your climate study.  
  • What time period do you want to simulate?    
  • The boundary conditions and forcing files included as part of the CESM release pertain to modern time periods: pre-industrial, present day and future scenarios. Configuring the CESM for past time periods requires that the investigator specify forcings and boundary conditions for the geologic time period of interest, including paleogeography, topography, and land surface conditions. Depending on the CESM configuration, the investigator may also need to provide, for example, bathymetry, atmospheric aerosols, etc.  The Paleo User Resources site provides tools and guidance for modifying forcing and boundary conditions. 
  • It may be useful to know whether others have used the current version of CESM to simulate your time period in case they would be willing to share their model setup. Posting a query on the CESM forums web page is an efficient way to look for collaborative opportunities. In addition, we encourage you to attend one of our Paleoclimate Working Group meetings to share your interest and results and hear about our activities and plans. This is also a great way to link up with other investigators who may be working on similar projects.

  • What configuration of CESM do you plan to use?    
  • Your research may allow a reduced model configuration. For example, you may be able to implement active land and atmosphere component models driven by prescribed SST and sea ice distributions. This may be a good place to start if you have limited computational time and storage allocation. What computer will you use to run your simulations?
  • A slab ocean model (SOM) is also available. The SOM is much faster and computationally more cost-effective than running the fully-coupled model with an active full-depth ocean component, which takes a few thousand model years to spin up to a quasi-equilibrium. See the CESM User's Guide for details on potential CESM configurations.
  • Do you have experience running or analyzing output from the CESM?
  • Running an "out-of-the-box" (OTB) pre-industrial CESM simulation and completing the CESM Tutorial are prerequisites for configuring a paleoclimate simulation.  
  • Follow the CESM Tutorial to become familiar with running the CESM model and changing the model forcing parameters.  Refer to the CESM User's Guide for the model version you plan to use to find more detailed information.
  • What computer will you use to run your simulations? Do you have allocated computer time and storage on the NCAR-Wyoming Supercomputers? 
  • Running the CESM at any resolution or configuration is computationally expensive and produces large amounts (Giga- to Tera- bytes) of output. This means you will need supercomputer access and storage space to carry out your simulations.
  • Information on access to the Yellowstone computer resources at the NCAR-Wyoming Supercomputing Center (NWSC) can be found here: http://www2.cisl.ucar.edu/docs/allocations.  Refer to the CESM User’s Guide for information on porting the CESM model to other computers.