The CSIRO Mk3L Model

TPAC offers access to the CSIRO Mk3L climate system model for use in our HPC environment.

The CSIRO Mk3L climate system model is freely available to the research community. To gain access to the model distribution, complete the online application form here.


  • Low-resolution version of the CSIRO climate system model
  • Coupled atmosphere-sea ice-ocean general circulation model
  • Designed to enable millennial-scale simulations of climate variability and change
  1. palaeoclimate reconstructions
  2. projections of future climate
  3. detection/attribution

Atmospheric model:

  • Based on the CSIRO Mk3 atmosphere model
  • Spectral general circulation model
  • Reduced horizontal resolution of R21 (  5:6;  3:2)
  • 18 vertical levels
  • Orbital parameter code
  • Dynamic-thermodynamic sea ice model
  • Land surface model (static vegetation)

Ocean model:

  • Based on the CSIRO Mk2 ocean model
  • z-coordinate general circulation model
  • Same horizontal grid as atmosphere model
  • 21 vertical levels
  • Gent-McWilliams eddy di usion

Coupled model:

  • Surface elds exchanged every one hour (3 atmosphere model timesteps for each ocean model timestep)
  • Coupling rigorously conserves heat and freshwater
  • Flux adjustments applied

Source code:

  • Designed for maximum portability across computer architectures
  • Should compile on any UNIX/Linux platform
  • Shared-memory parallelism achieved using OpenMP
  • Dependence on external libraries restricted to netCDF and FFTW
  • Loop structure optimised for serial architectures