Also known as
Model type Modular
Model part of larger framework
Incorporated models or components:


Spatial dimensions
Spatial extent
Model domain Marine
One-line model description Regional Ocean Modeling System
Extended model description ROMS is a Free-surface, terrain-following, orthogonal curvilinear, primitive equations ocean model. Its dynamical kernel is comprised of four separate models including the nonlinear, tangent linear, representer tangent linear, and adjoint models. It has multiple model coupling (ESMF, MCT) and multiple grid nesting (composed, mosaics, refinement) capabilities. The code uses a coarse-grained parallelization with both shared-memory (OpenMP) and distributed-memory (MPI) paradigms coexisting together and activated via C-preprocessing.

flow dynamics, wave dynamics, physical oceanography,

First name Hernan G.
Last name Arango
Type of contact Model developer
Institute / Organization IMCS, Rutgers University
Postal address 1 71 Dudley Road
Postal address 2
Town / City New Brunswick
Postal code 08901-8521
State New Jersey
Country United States
Email address
Phone (732) 932-6555 x266

First name Alexander
Last name Shchepetkin
Type of contact Model developer
Institute / Organization
Postal address 1
Postal address 2
Town / City
Postal code
Email address

Supported platforms Unix, Linux, Windows
Other platform CygWin
Programming language Fortran90
Other program language
Code optimized
Multiple processors implemented
Nr of distributed processors
Nr of shared processors
Start year development 1998
Does model development still take place? Yes
If above answer is no, provide end year model development
Code development status Active
When did you indicate the 'code development status'? 2020
Model availability As code
Source code availability
(Or provide future intension)
Through web repository
Source web address
Source csdms web address
Program license type Other
Program license type other MIT/X License, see License_ROMS.txt.
Memory requirements Depends on application but it is relatively small in distributed-memory since only the tile partition is allocated for global and local arrays. All the state model variables are dynamically allocated and passed as arguments to the computational routines via de-referenced pointer structures.
Typical run time Depends on application and resolution. Usually it takes several hours to run a realistic application for a simulation month.

Describe input parameters There are hundreds of input parameters for the physical, ecosystem, and sediment models. In addition, there are input scripts for floats, stations, model coupling, and data assimilation.
Input format ASCII
Other input format ASCII (input scripts), NetCDF (input fields).
Describe output parameters There are hundreds of output parameters and fields that are written to several NetCDF files.
Output format
Other output format NetCDF, CF-convections.
Pre-processing software needed? No
Describe pre-processing software
Post-processing software needed? Yes
Describe post-processing software Yes, ROMS I/O is via NetCDF and follows CF-standard conventions. Therefore, any visualization software for NetCDF files can be used for pre- and post-processing.
Visualization software needed? Yes
If above answer is yes
Other visualization software Yes, a plotting package is provided. It uses the NCAR's graphics Library. Any visualization package for NetCDF files can be used, like IDL, Matlab, and others.

Describe processes represented by the model ROMS resolved fast (gravity waves) and slow (Rossby waves) dynamics. Hydrostatic approximation but there is a nonhydrostatic version of ROMS.
Describe key physical parameters and equations Navier-Stokes primitive equations. Bio-optical, biogeochemical, and ecosystem models equations. Cohesive and non cohesive sediment equations. Several vertical turbulece equations (KPP, GLS, MY-2.5). Air-Sea interaction coupling equations (COARE). Bottom boundary layer model equations.
Describe length scale and resolution constraints Estuary, regional, and basin scales. There are couple of global applications.
Describe time scale and resolution constraints Hours, days, seasons. It also can be used for climate research (decades).
Describe any numerical limitations and issues ROMS has a predictior-corrector algorithm that is efficient and accuarate. This class of model (terrain-following) exhibits stronger sensitivity to topography which results in pressure gradient errors. ROMS has several pressure gradient algorithms that minimize this problem.

Describe available calibration data sets There are several idealized and realistic test cases. Some of the idealized test cases have quasi-analytical solutions.
Upload calibration data sets if available:
Describe available test data sets We have a website for test problems:
Upload test data sets if available:
Describe ideal data for testing We have test cases for both laboratory and field observations. In the past, we have used data from rotating tanks.

Do you have current or future plans for collaborating with other researchers? Yes, we work with several modeling groups around the world.
Is there a manual available? Yes
Upload manual if available:
Model website if any
Model forum / discussion board
Comments The documentation about ROMS can be found in WikiROMS:

There is a very active ROMS user's forum:


This part will be filled out by CSDMS staff

OpenMI compliant No but possible
BMI compliant Yes
WMT component Yes
PyMT component
Can be coupled with:
Model info
Hernan G. Arango
Citation indices ROMS
Nr. of pubs: 407
Citations: 12810
h-index: 48
Qrcode ROMS.png
Link to this page




Citation indices ROMS
Nr. of pubs: 407
Citations: 12810
h-index: 48

Featured publication(s)YearModel describedType of ReferenceCitations
Haidvogel, D.B.; Arango, H.; Budgell, W.P.; Cornuelle, B.D.; Curchitser, E.; Di Lorenzo, E.; Fennel, K.; Geyer, W.R.; Hermann, A.J.; Lanerolle, L.; Levin, J.; McWilliams, J.C.; Miller, A.J.; Moore, A.M.; Powell, T.M.; Shchepetkin, A.F.; Sherwood, C.R.; Signell, R.P.; Warner, J.C.; Wilkin, J.; 2008. Ocean forecasting in terrain-following coordinates: Formulation and skill assessment of the Regional Ocean Modeling System. Journal of Computational Physics, 227, 3595–3624. 10.1016/
(View/edit entry)
Model overview 776
Shchepetkin, Alexander F.; McWilliams, James C.; 2005. The regional oceanic modeling system (ROMS): a split-explicit, free-surface, topography-following-coordinate oceanic model. Ocean Modelling, 9, 347–404. 10.1016/j.ocemod.2004.08.002
(View/edit entry)
Model application 2523
Song, Yuhe; Haidvogel, Dale; 1994. A Semi-implicit Ocean Circulation Model Using a Generalized Topography-Following Coordinate System. Journal of Computational Physics, 115, 228–244. 10.1006/jcph.1994.1189
(View/edit entry)
Model overview 565
See more publications of ROMS




Input Files

Output Files