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Description

The Poseidon Ocean Model was designed and developed by Professor Paul Schopf, George Mason University. It is a 3-dimensiona, hybrid coordinate, primitive equation ocean circulation model.

George Mason University: Poseidon Ocean Model

Features of V5

• Non-Boussinesq dynamics:
  Because of the generalized coordinate treatment in poseidon, we use a Jacobian finite volume treatment of the pressure gradient force. The choice that was made is to use S. J. Lin's (1997) form, which reduces to the Montgomery potential form if the coordinate is isopycnal, and which maintains the irrotationality constraint around closed contours of geopotential or bottom pressure. A detailed description of the method is detailed here(pdf)
  
  
• Finite Volume numerics
  
  
• Arbitrary orthogonal curviliear horizontal coordinates<
  
  
• Generalized vertical coordinates
  
  • Quasi-Isopycnal/Pressure hybrid
  • Mixed Layer/Buffer Zone/Isopycnal hybrid
    
    
• B or C grid (Run-time configuration)
  
  
• Reduced gravity or full barotropic (Run-time option)
  
  
• Split-explicit barotropic treatment (Hallberg, 1997)
  
  
• ALE technique for splitting horizontal and vertical coordinates
  
  
• Implicit vertical diffusion
  
  
• Fortran-95 modularized>
  
  
• Uses GEMS parallelization libraries and message-passing paradigm for efficient execution on a variety of platforms:
  
  • Linux 1cpu (NAG f95)
  • Mac OSX (NAG f95 or IBM XLF8.1)
  • IBM SP cluster (NCAR blackforest and bluesky)
  • Compaq Alpha (GSFC halem)
  • SGI Altix 3700 (GMU SCS)
    
    
• Vector-invariant formulation with 2nd or 4th order advection of potential vorticity
  
  
• Jacobian form for pressure term (Lin, 1997)
  
  
• KPP-like or bulk turbulent mixed layers
  
  
• Run-time selectable tracer advection schemes: 2nd, 3rd or 4th order advection
  
  
• Arbitrary bottom topography:
  
  • Minimum ocean depth of millimeters
  • No smoothing required
    
• Any number of passive tracers
  
  
• Variable short wave optical properties>
  
  
• Compile-time selection of equations of state:
  
  • UNESCO
  • Wright
  • Linear
  • Quadratic
  • Roll-your-own
    
• Smagorinsky Laplacian or Biharmonic viscosity (Griffies-Hallberg, 2000)
  
  
• Shapiro filter for mass, momentum or tracers
  
  
• Shapiro filter for null mode removal on B-grid
  
  
• Open upper boundary conditions