Conformal Cubic Grid

To the best of our knowledge, CCAM was the first three-dimensional atmospheric model to employ a cubic grid.  CCAM employs a Conformal Cubic grid which is realised by projecting a cube onto the surface of a sphere.

CCAM also supports a Schmidt transformation that allows the global grid to be focused over a particular region.  This transform can improve the resolution for the region at the expense of reducing the resolution for the opposite side of the globe.  When using highly stretched grids (e.g., Schmidt factor > 3 ), CCAM employs a nudging method based on scale-selective filters which prevents the build-up of errors in the coarse grid region.  In this way, CCAM can use a multiply nested grid approach that is particularly effective for simulating the regional climate.