The MIT GCM
 Dimitris Menemenlis, JPL

The MIT GCM (MIT General Circulation Model) is a numerical model for studying the ocean and atmosphere. It is capable of simulating these fluids at a wide range of scales and can resolve many different processes. It has a non-hydrostatic capability (Marshall et al., 1997a & b) and uses the finite volume method to accurately represent the bottom boundary position (Adcroft etal., 1998). The MIT GCM

  • can be used to study both atmospheric and oceanic circulation,
  • has a non-hydrostatic capability (Marshall et al., 1998),
  • supports horizontal orthogonal curvilinear coordinates,
  • has a finite volume treatment of topography,
  • supports a wide range of physical parameterizations,
  • has tangent linear and adjoint code, maintained alongside the forward model (Marotzke et al., 1999), and
  • can run on a pc, a workstation, or a parallel computer using a flexible
    domain decomposition that supports a wide variety of memory models and
    computing platforms.

MIT GCM is freely available and can be downloaded from the following web site (http://mitgcm.org/sealion/). The web site also includes extensive usage notes and documentation of the model's characteristics and capabilities. Of particular interest to this project is a global configuration of the MIT GCM, which is maintained at JPL (Jet Propulsion Laboratory) as part of the ECCO (Estimating the Climate and Circulation of the Ocean http://www.ecco-group.org/) consortium and which is used for assimilating a wide variety of satellite and in-situ measurements. The coupling of the MIT ocean model with the UCLA atmospherioc model will allow us to test the impact of JPL ocean state estimates (http://ecco.jpl.nasa.gov/external/) on the short-term (seasonal to annual) prediction capability of a state-of-the-art climate model.

References

  • Marshall, J., C. Hill, L. Perelman, and A. Adcroft, (1997a) Hydrostatic, quasi-hydrostatic, and nonhydrostatic ocean modeling J. Geophysical Res., 102(C3), 5733-5752.
  • Marshall, J., A. Adcroft, C. Hill, L. Perelman, and C. Heisey, (1997b) A finite-volume, incompressible Navier Stokes model for studies of the ocean
    on parallel computers, J. Geophysical Res., 102(C3), 5753-5766.
  • Adcroft, A.J., Hill, C.N. and J. Marshall, (1998) Representation of topography by shaved cells in a height coordinate ocean model Mon Wea Rev, vol 125, 2293-2315
  • Marshall, J., Jones, H. and C. Hill, (1998) Efficient ocean modeling using non-hydrostatic algorithms Journal of Marine Systems, 18, 115-134
  • Marotzke, J, Giering,R., Zhang, K.Q., Stammer,D., Hill,C., and T.Lee, (1999) Construction of the adjoint MIT ocean general circulation model and application to Atlantic heat transport variability J. Geophysical Res., 104(C12), 29,529-29,547.