16.3. Comparison of ROMS and CROCO versions

Models	CROCO	ROMS-UCLA	ROMS-Rutgers / COASWT
Origin	UCLA-IRD-INRIA- IFREMER-SHOM-CNRS	UCLA	UCLA-Rutgers-USGS
Maintenance	IRD-INRIA-IFREMER- SHOM-CNRS	UCLA	Rutgers-USGS
Realm	Europe-World	US West Coast	US East Coast
Introductory year	1999 (AGRIF) 2016 (CROCO)	2002	1998

CODE FEATURES

Models	CROCO	ROMS-UCLA	ROMS-Rutgers / COASWT
Parallelization	MPI or OpenMP (Hybrid branch exists)	Hybrid MPI-OpenMP	MPI or OpenMP
Nesting	Online at barotropic level	Off-line (On-line at baroclinic level and not yet operational)	Off-line
Data assimilation	3DVAR	3DVAR	4DVAR
Wave-current interact.	McWilliams et al. [2004]	McWilliams et al. [2004]	Mellor [2003] McWilliams et al. [2004]
Air-sea coupling	OASIS-MCT	Home made	MCT
Sediment Dynamics	Blaas et al. [2007] MUSTANG	Blaas et al. [2007]	Blaas et al. [2007] Warner et al. [2008]
Biogeochemistry	NPZD Gruber et al. [2006], PISCES	NPZD Gruber et al. [2006]	EcoSim, NEMURO, NPZD Franks, NPZD Powell, Fennel
Sea ice	none	none	Budgell [2005]
Vertical mixing	KPP, GLS	KPP, GLS	KPP, GLS
Wetting-Drying	Warner et al. [2013]	none	Warner et al. [2013]

TIME STEPPING

Models	CROCO	ROMS-UCLA	ROMS-Rutgers / COASWT
2D momentum	Generalized FB AB3-AM4	Generalized FB AB3-AM4	LF-AM3 with FB feedback
3D momentum	LF-AM3	LF-AM3	AB3
Tracers	LF-AM3 with stabilizing correction for isopycnal hyperdiffusion	LF-AM3 with stabilizing correction for isopycnal hyperdiffusion	LF-TR with explicit geopotential diffusion (no stabilizing correction : strong stability constraint)
Internal waves	LF-AM3 with FB feedback	LF-AM3 with FB feedback	Generalized FB (AB3-TR)
Coupling stage	Predictor	Corrector

STABILITY CONSTRAINTS (Max Courant number)

Models	CROCO	ROMS-UCLA	ROMS-Rutgers / COASWT
2D	1.78	1.78	1.85
3D advection	1.58	1.58	0.72
Coriolis	1.58	1.58	0.72
Internal waves	1.85	1.85	1.14