compass

Compass (Configuration Of Model for Prediction Across Scales Setups) is a python package that provides an automated system to create E3SM initial conditions and perform other testing of MPAS (Model for Prediction Across Scales) ocean and land-ice components. The development version of compass is kept closely synchronized with the E3SM repository and MALI-Dev repository. Release versions will be compatible with specific E3SM tags.

Many compass test cases are “realistic” in the sense that they use data sets from observations to create global and regional meshes, initial conditions, and boundary conditions. The remaining test cases are idealized: benchmarks, convergence tests, regression tests and process studies (Fig. 1).

Figure 1. A compass test case showing the vorticity in an idealized ocean basin.

Compass will be the tool used to create new land-ice and ocean meshes and initial conditions for E3SM v3 and beyond. We note that compass does not provide the tools for creating many of the files needed for full E3SM coupling, e.g. mapping files between different E3SM grids. This process requires expert help from the E3SM development team.

The compass python package defines the test cases along with the commands to list and set up both test cases and test suites (groups of test cases). Most test cases run either MPAS-Ocean or MALI in standalone mode, configuring the initial conditions, namelists and streams files required to perform a simulation. One of the benefits of using compass over attempting to run one of the MPAS components directly is that compass begins with default values for all namelists and streams, modifying only those options where the default is not appropriate. In this way, compass requires little alteration as the MPAS components themselves evolve and new functionality is added. Compass provides new and existing users out-of-the-box model configurations to ensure rapid, reproducible, and flexible development and standalone execution of these two E3SM components.