The DieCAST (Dietrich Center for Air Sea Technology) model is a
z-level ocean and lake model patterned after the Sandia Ocean Modeling
System (SOMS). The original DieCAST model is hydrostatic, incompressible, rigid-lid, partially
implicit, and fully conservative.
The numerical differences from the SOMS model
stem only from using an Arakawa A grid instead of the Arakawa C grid used by
SOMS. The DieCAST model is simpler and requires less computation per time step
than the SOMS model. It is also stable with substantially longer time step. Both
DieCAST and SOMS use higher order treatment of the generally dominat terms in
ocean dynamics, i.e. pressure gradient and Coriolis. This leads to accurate and
robust (stable with realistically small dissipation) models.
In the latest version, the model includes
the non-hydrostatic, free-surface, immersed boundary method (IBM) and
two-ways coupling capabilities.