Begin Main Content

Description

The Modular Ocean Model (MOM) was designed and developed by researchers at the Geophysical Fluid Dynamics Laboratory (GFDL/NOAA Department of Commerce). It is a 3-dimensional, z-coordinate, primitive equation ocean circulation model.

The GFDL Modular Ocean Model V.4 (MOM4) is a finite difference version of the ocean primitive equations under the assumptions of Boussinesq and hydrostatic approximation. Here we summaries some basic information; details are available from Gnanadesikan et al. (2005). It uses spherical coordinates in the horizontal with a staggered Arakawa B grid and the z-coordinate in the vertical. The ocean surface boundary is computed as an explicit free surface. The zonal resolution is 1�. The meridional resolution varies between 1� in the mid-latitudes and 1/3� in the tropics to resolve the equatorial wave guide. A tripolar grid is used to resolve cross-polar flow (Murray, 1996). There are 50 vertical levels with 22 uniformly spaced in the upper 220 m. The thickness gradually increases to a value of 366.6 m at the bottom located at 5500m. Vertical mixing follows the non-local K-profile parameterization of Large et al. (1994). The horizontal mixing of tracers uses the isoneutral method pioneered by Gent and McWilliams (1990). The horizontal mixing of momentum uses an anisotropic viscosity scheme that produces large viscosity in the east-west direction, but relatively small viscosity in the north-south direction outside of boundary currents, similar to that of Large et al. (2001).

Publications

• MOM 3.0 Manual (pdf)
• Formulation of an ocean model for global climate simulations( pdf)