1/15° North Atlantic and Mediterranean configuration (PAM)

• Earth's spericity: local gravity directed towards the centre of Earth
• Relatively shallow water: ocean depth small in relation to the Earth's radius
• Hydrostatic: equilibrium between the vertical pressure gradiant and the floatability
• Boussinesq values: variations in density are not taken into account apart from their contribution to floatability
• Incompressibility: the three-dimensional divergence of the velocity field is considered to be nil
• 1.5 order closure turbulence scheme
• Non-linear equation of state couples the two active trace indices (temperature and salinity)
• Rigid lid approximation

• Model state variables: temperature, salinity, zonal and meridian velocity, barotropic stream function and vertical diffusivity coefficient
• Atmospheric forcing: zonal and meridonal wind stress components, total heat flux, retroactive term, solar flux, precipitation and runoff minus evaporation budget, restoring surface salinity
• Diagnostic variables: mixed layer depth (one density diagnostic, one vertical mixing diagnostic), sea level elevation, barotropic height, dynamic height, mass transport by density class through sections, meridional heat transport

• Diffusion : laplacian isopycnal operator (100 m2/s)
• Viscosity : bilaplacian horizontal operator (-9E9 m2/s)
• Energy and enstrophy conserving advection scheme
• Regionalisation of parameterizations of Gent & McWilliams (non operational)
• TKE (turbulent kinetic energy) vertical mixing model
• Partial slip lateral boundary friction condition
• Non linear bottom friction
• Bottom boundary condition
• Z vertical coordinate

Towards Reynaud climatology (T,S) at the Gibraltar Strait, in the Gulf of Cadiz. This restoring increases from 500 m to 1000 m, then remains constant to the bottom (~30 days).

Rotated Mercator 1/15° grid in Atlantic, 1/16° in Mediterranean sea, 3 to 7 Km. Number of points : 1022 x 1288


PAM grid resolution

43 levels. Resolution from 6 m at the surface to 200 m at the bottom in the Mediterranean, and 300m at the bottom in the Atlantic


PAM vertical reoslution (see yellow diamonds)

Flux formulation with retroaction betwwen model surface temperature and atmosphere, computed from Reynolds SST (40 W/m2) and equivalant restoring towards climatologic surface salinity (Barnier, Siefridt et al. 1995). The monthly climatological flow of 24 main rivers is taken into account in the evaporation minus precipitation budget. A parameterization of the penetrating heat flux is used.

• South boundary at 9°N : buffer zone where temperature and salinity are restored towards Reynaud climatology, restoring coefficient from 3 to 100 days). Possible activation an opened radiative boundary forced by daily data from a 1/3° simulation (non activated in operational)
• North boundary at 70°N : buffer zone where temperature and salinity are restored towards Reynaudclimatology (restoring coefficient from 3 to 100 days).

ERA-40 (1988-2002) or ECMWF daily operational analysis (1998-2006). Forcing concerns: zonal and meridional wind stress component, solar flux, total heat flux (solar, infrared, sensible, latent), evaporation, precipitation.

Monthly Temperature and Salinity climatology from Reynaud for Atlantic and MEDATLAS for Mediterranean.

Smith et Sandwell, 1997.

• 50 Gigabytes of memory
• 4000 CPU hours
• 100 Gigabytes of output (daily output)

• PSY2V1
• PSY2V2