CESM Models

CCSM4: Notable Improvements


  1. New treatments of cloud and ice-phase processes;
  2. Improved representation of the interactions among water vapor, solar radiation, and terrestrial thermal radiation;
  3. New treatment of the effects of aerosols, including prognostic sulfate, on the reflection and absorption of solar radiation; and
  4. New dynamical frameworks suitable for modeling atmospheric chemistry.


  1. Improved performance and scalability on parallel supercomputers;
  2. Faster multi-way communication among the component models; and
  3. New communications infrastructure.


  1. New methods to enable simulation of the terrestrial carbon cycle;
  2. New methods to enable simulation of dynamic vegetation; and
  3. Improvements in land-surface physics to reduce temperature biases; and
  4. New load balancing implementation results in substantial performance improvement.


  1. Improvements to the representation of the ocean mixed layer;
  2. Inclusion of solar heating by chlorophyll; and
  3. New infrastructure for studying vertical mixing in the ocean.


  1. New advanced sea ice rheology;
  2. Explicit ice-thickness distribution physics;
  3. Explicit treatment of brine pockets; and
  4. Improved scheme for horizontal advection of sea ice.

Complete System

  1. New portability for vector and Linux supercomputers;
  2. New, easy-to-use methods to run IPCC climate-change experiments;
  3. Flexibility to simulate climate over a wide range of spatial resolutions with greater fidelity; and
  4. New built-in test facilities suitable for validating installation and verifying some types of model changes.