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The Modular Ocean Model (MOM) is the canonical ocean climate model use by many researchers around the world. The model’s origins date back to the community code first developed by Kirk Bryan and Mike Cox in the 1960's-1980's, and to which many other ocean climate models can trace their origins. Ron Pacanowski, Keith Dixon and Tony Rosati fundamentally reworked these older codes into a much more modern format in the early 1990’s, and Steve Griffies has led the continued development of MOM since 2000. However, MOM is truly a community code, and many people, both inside GFDL and around the world, have contributed fundamentally to its successful development over the years.

  • MOM5.0 was released in 2012, and extends the capabilities of MOM4.1 with a novel "Lagrangian-blobs" treatment of overflows, and a prototype C-grid discretization.
  • MOM4.1 was most recently released in December 2009 (click here for the MOM4.1 manual: ~7Mb).  This code allows for the following added functionality relative to MOM4.0:
    1. the inclusion of non-Boussinesq effects (relevant for studying sea-level)
    2. alternative vertical coordinates such as p* and z*.
We highlight also the release of the CM2.1 climate model as a test case with the December 2009 version of MOM4p1.
  • MOM4.0 presents an extensive update in parameterizations and streamlined capabilities relative to MOM3. There were four sub-releases of this code during the period Jan2004 until May2005.  Click here for the MOM4.0 manual (~2Mb).
  • MOM3 is a z-coordinate model released in 1999. It is no longer supported by GFDL, though the MOM3 manual can be downloaded here(~5Mb).
  • MOM2.2 was released in 1996. It is no longer supported by GFDL, though the MOM2 manual can be downloaded here (~2Mb).

Plans for MOM6

MOM6 represents a significant reengineering of MOM employing an Arakawa C-grid for the horizontal (instead of a B-grid) and a radically different approach for the treatment of the vertical coordinate. MOM6 uses the ALE algorithm (Arbitrary-Lagrangian-Eulerian, [Hirt et al., 1974]) in the vertical that is coordinate-agnostic and thus allows remapping to any coordinate system as needed. Using ALE in the vertical also removes the advection CFL restriction on time-step so that the model is unconditionally stable to thin (or vanishing) layers.

In addition to generalized vertical coordinates, new capabilities in MOM6 include the conservative representation of wetting and drying essential for evolving ice shelf grounding lines, along with key physical parameterizations including new scale-aware parameterizations for eddy-permitting regimes. MOM6 will be the ocean code used in the next GFDL coupled climate model.

MOM6 will also be made available under an open-source software-model which means that in addition to supported releases of the source code it will be possible for community developers to obtain and collaborate on the latest development branches. The transition to open-source is planned to coincide with the first release of software and documentation. In the meantime, early access to MOM6 will be considered on a case-by-case basis.