The original Gent-Cane model (Gent and Cane, 1989) was developed for
modeling the equatorial pacific on a stretched longitude/latitude A-grid.
Fourth order approximations to
horizontal spatial derivatives combined with a fourth order (in time)
Lorenz cycle provided a high order discretization advantageous for high
resolution runs. The original vertical structure was simply
a mixed layer at the surface and sigma layers down to a
bottom layer of no motion. The surface mixed layer could be either a
true layer with no mass exchange with lower layers, or could be kept
at a fixed thickness. Restoration of SST at the surface provided the
surface heat flux and Shapiro filters, reducing the order near
land boundaries, provided a minimal amount of horizontal diffusion.
The vertical diffusion of momentum and heat was explicit.
Most of the horizontal features have been kept in the present version.
The 4th order time and space (horizontal) discretization has been
maintained, the Shapiro filters (reduced, conservative, narrow passage
modifications,...) are still used, and most of the old options remain.
The only major exception is that the reduced gravity setup
(assuming no motion at depth) is not currently supported in this
version (but easily could be, if the need arises ...).
Descriptions of most of the features of the current model can be found in
Keith Rodger's documentation. The major changes from the original Gent/Cane model
are the vastly improved I/O handling,
a barotropic solver, a new ocean mixed layer parameterization
and an atmospheric mixed layer (AML).
The I/O utilities, written by
allows the model to be run with
a constant bathymetry assumption rather than the reduced gravity assumption.
has been generalized to use a combination of
adjustment with a Kraus-Turner parameterization of wind mixing
Richardson number dependent mixing ,
Large et al. K-profile parameterisation (KPP) ,
Dake Chen 's ocean
hybrid vertical mixing scheme . As either an alternative
or in addition to the Shapiro filter,
Isopycnal diffusion has been added, with an option to
make it purely isopycnal or horizontal. The
Gent-McWilliams eddy parameterization is also available, with
variable coefficient as suggested by Visbeck et al.
Density is computed from both temperature and salinity by a
efficient high order approximation to the UNESCO formula, and passive
tracers can be implemented by specifying initial conditions in a user
supplied data file.
atmospheric mixed layer (AML) computes the surface fluxes rather than
restoration to SST and SSS, with data files prescribing wind, air
temperature and humidity over land, clouds, solar radiation and
Thermodynamic ice has been added by
as an integral part of
has been coded, but has not been tested.
the senq libraries consisting of
easy FORTRAN-callable direct access
IO library (daio)
a simplified interface to
ingrid plotting routines