1. Governing Equations

Related CPP options:

SOLVE3D

solve 3D primitive equations

UV_COR

Activate Coriolis terms

UV_ADV

Activate advection terms

NBQ

Activate non-boussinesq option

CROCO_QH

Activate quasi-hydrostatique option

MRL_WCI

Activate wave-current interactions

Preselected options:

# define SOLVE3D
# define UV_COR
# define UV_ADV
# undef  NBQ
# undef  CROCO_QH
# undef  MRL_WCI

Presentation

By default (#undef NBQ), CROCO solves the primitive equations as in ROMS, from which it inherited the robustness and efficiency of its time-splitting implementation (Shchepetkin & McWilliams, 2005; Debreu et al., 2012) and the NBQ option proposes an extension for non-hydrostatic applications. In CROCO’s time-splitting algorithm, the ”slow mode” is similar to ROMS internal (baroclinic) mode described in Shchepetkin & McWilliams (2005), whereas the ”fast mode” can include, in addition to the external (barotropic) mode, the pseudo-acoustic mode that allows computation of the non-hydrostatic pressure within a non-Boussinesq approach (Auclair et al., 2018). In this case, the slow internal mode is also augmented by a prognostic vertical velocity equation, replacing the hydrostatic equation. Another option (CROCO_QH) extends the PE equations to form the quasi-hydrostatic equations, relaxing the hypothesis of weak horizontal Coriolis force (Marshall et al., 1997), thus adding a non-hydrostatic pressure component that is solved diagnostically. Then, another option (MRL_WCI) treats the wave-averaged equations (McWilliams et al., 2004) with wave-current interaction terms that are both conservative and non-conservative (needing parametrizations).