Run the Reference configurations
NEMO is distributed with a set of reference configurations allowing both the user to set up his own first applications and the developer to test/validate his NEMO developments (using SETTE package).
Attention!
Concerning the configurations, the NEMO System Team is only in charge of the so-called reference configurations described below.
Hint
Configurations developed by external research projects or initiatives that make use of NEMO are welcome to be publicized through the website by filling up the form :website:`to add an associated project<projects/add>`.
How to compile an experiment from a reference configuration
To compile the ORCA2_ICE_PISCES reference configuration using :file:`makenemo`, one should use the following, by selecting among available architecture file or providing a user defined one:
$ ./makenemo -r 'ORCA2_ICE_PISCES' -m 'my_arch' -j '4'
A new EXP00
folder will be created within the selected reference configurations,
namely ./cfgs/ORCA2_ICE_PISCES/EXP00
.
It will be necessary to uncompress the archives listed in the above table for
the given reference configuration that includes input & forcing files.
Then it will be possible to launch the execution of the model through a runscript (opportunely adapted to the user system).
List of Configurations
All forcing files listed below in the table are available from |DOI data|_
Configuration | Component(s) | Archives (input & forcing files) | ||||
---|---|---|---|---|---|---|
Name | O | S | T | P | A | |
AGRIF_DEMO | X | X | X | AGRIF_DEMO_v4.0.tar, ORCA2_ICE_v4.0.tar | ||
AMM12 | X | AMM12_v4.0.tar | ||||
C1D_PAPA | X | INPUTS_C1D_PAPA_v4.0.tar | ||||
GYRE_BFM | X | X | none | |||
GYRE_PISCES | X | X | X | none | ||
ORCA2_ICE_PISCES | X | X | X | X | ORCA2_ICE_v4.0.tar, INPUTS_PISCES_v4.0.tar | |
ORCA2_OFF_PISCES | X | X | ORCA2_OFF_v4.0.tar, INPUTS_PISCES_v4.0.tar | |||
ORCA2_OFF_TRC | X | ORCA2_OFF_v4.0.tar | ||||
ORCA2_SAS_ICE | X | ORCA2_ICE_v4.0.tar, INPUTS_SAS_v4.0.tar | ||||
SPITZ12 | X | X | SPITZ12_v4.0.tar |
Legend for component combination
O for OCE, S for SI3, T for TOP, P for PISCES and A for AGRIF
AGRIF_DEMO
AGRIF_DEMO
is based on the ORCA2_ICE_PISCES
global configuration at 2° of resolution with
the inclusion of 3 online nested grids to demonstrate the overall capabilities of AGRIF in
a realistic context (including the nesting of sea ice models).
The configuration includes a 1:1 grid in the Pacific and two successively nested grids with odd and even refinement ratios over the Arctic ocean, with the finest grid spanning the whole Svalbard archipelago that is of particular interest to test sea ice coupling.

The 1:1 grid can be used alone as a benchmark to check that the model solution is not corrupted by grid exchanges. Note that since grids interact only at the baroclinic time level, numerically exact results can not be achieved in the 1:1 case. Perfect reproducibility is obtained only by switching to a fully explicit setup instead of a split explicit free surface scheme.
AMM12
AMM12
stands for Atlantic Margin Model at 12 km that is
a regional configuration covering the Northwest European Shelf domain on
a regular horizontal grid of ~12 km of resolution (see :cite:`ODEA2012`).

This configuration allows to tests several features of NEMO specifically addressed to the shelf seas.
In particular, AMM12
accounts for vertical s-coordinates system, GLS turbulence scheme,
tidal lateral boundary conditions using a flather scheme (see more in BDY
).
Boundaries may be completely omitted by setting ln_bdy = .false.
in nambdy
.
Sample surface fluxes, river forcing and an initial restart file are included to test a realistic model run
(AMM12_v4.0.tar
).
Note that, the Baltic boundary is included within the river input file and is specified as a river source, but unlike ordinary river points the Baltic inputs also include salinity and temperature data.
C1D_PAPA

C1D_PAPA
is a 1D configuration for the `PAPA station`_ located in
the northern-eastern Pacific Ocean at 50.1°N, 144.9°W.
See :gmd:`Reffray et al. (2015) <8/69/2015>` for the description of
its physical and numerical turbulent-mixing behaviour.
ln_c1d = .true.
in namdom
and
has a horizontal domain of 1x1 grid point.Data provided with INPUTS_C1D_PAPA_v4.2.tar
file account for:
- :file:`forcing_PAPASTATION_1h_y201[0-1].nc`: ECMWF operational analysis atmospheric forcing rescaled to 1h (with long and short waves flux correction) for years 2010 and 2011
- :file:`init_PAPASTATION_m06d15.nc`: Initial Conditions from observed data and Levitus 2009 climatology
- :file:`chlorophyll_PAPASTATION.nc`: surface chlorophyll file from Seawifs data
GYRE_BFM
GYRE_BFM
shares the same physical setup of GYRE_PISCES,
but NEMO is coupled with the `BFM`_ biogeochemical model as described in ./cfgs/GYRE_BFM/README
.
GYRE_PISCES
GYRE_PISCES
is an idealized configuration representing a Northern hemisphere double gyres system,
in the Beta-plane approximation with a regular 1° horizontal resolution and 31 vertical levels,
with PISCES BGC model :cite:`gmd-8-2465-2015`.
Analytical forcing for heat, freshwater and wind-stress fields are applied.
This configuration acts also as demonstrator of the user defined setup
(ln_read_cfg = .false.
) and grid setting are handled through
the &namusr_def
controls in :file:`namelist_cfg`:
Note that, the default grid size is 30x20 grid points (with nn_GYRE = 1
) and
vertical levels are set by jpkglo
.
The specific code changes can be inspected in :file:`./src/OCE/USR`.
Running GYRE as a benchmark
nn_GYRE
(integer multiplier scaling factor), as described in the following table:nn_GYRE |
jpiglo |
jpjglo |
jpkglo |
Equivalent to |
---|---|---|---|---|
1 | 30 | 20 | 31 | GYRE 1° |
25 | 750 | 500 | 101 | ORCA 1/2° |
50 | 1500 | 1000 | 101 | ORCA 1/4° |
150 | 4500 | 3000 | 101 | ORCA 1/12° |
200 | 6000 | 4000 | 101 | ORCA 1/16° |
ln_bench = .true.
in &namusr_def
to
avoid problems in the physics computation and that
the model timestep should be adequately rescaled.nn_GYRE = 150
, equivalent to an ORCA 1/12° grid,
the timestep rn_rdt
should be set to 1200 seconds
Differently from previous versions of NEMO, the code uses by default the time-splitting scheme and
internally computes the number of sub-steps.ORCA2_ICE_PISCES
ORCA2_ICE_PISCES
is a reference configuration for the global ocean with
a 2°x2° curvilinear horizontal mesh and 31 vertical levels,
distributed using z-coordinate system and with 10 levels in the top 100m.
ORCA is the generic name given to global ocean Mercator mesh,
(i.e. variation of meridian scale factor as cosinus of the latitude),
with two poles in the northern hemisphere so that
the ratio of anisotropy is nearly one everywhere
This configuration uses the three components
- |OCE|, the ocean dynamical core
- |ICE|, the thermodynamic-dynamic sea ice model.
- |MBG|, passive tracer transport module and PISCES BGC model :cite:`gmd-8-2465-2015`
All components share the same grid. The model is forced with CORE-II normal year atmospheric forcing and it uses the NCAR bulk formulae.
Ocean Physics
horizontal diffusion on momentum: | the eddy viscosity coefficient depends on the geographical position. It is taken as 40000 m2/s, reduced in the equator regions (2000 m2/s) excepted near the western boundaries. |
---|---|
isopycnal diffusion on tracers: | the diffusion acts along the isopycnal surfaces (neutral surface) with an eddy diffusivity coefficient of 2000 m2/s. |
Eddy induced velocity parametrization: | With a coefficient that depends on the growth rate of baroclinic instabilities (it usually varies from 15 m2/s to 3000 m2/s). |
lateral boundary conditions: | Zero fluxes of heat and salt and no-slip conditions are applied through lateral solid boundaries. |
bottom boundary condition: | Zero fluxes of heat and salt are applied through the ocean bottom. The Beckmann [19XX] simple bottom boundary layer parameterization is applied along continental slopes. A linear friction is applied on momentum. |
convection: | The vertical eddy viscosity and diffusivity coefficients are increased to 1 m2/s in case of static instability. |
time step: | is 5400sec (1h30') so that there is 16 time steps in one day. |
ORCA2_OFF_PISCES
ORCA2_OFF_PISCES
shares the same general offline configuration of ORCA2_ICE_TRC
,
but only PISCES model is an active component of TOP.
ORCA2_OFF_TRC
ORCA2_OFF_TRC
is based on the ORCA2 global ocean configuration
(see ORCA2_ICE_PISCES for general description) along with
the tracer passive transport module (TOP),
but dynamical fields are pre-calculated and read with specific time frequency.Pre-calculated dynamical fields are provided to NEMO using
the namelist &namdta_dyn
in :file:`namelist_cfg`,
in this case with a 5 days frequency (120 hours):
Input dynamical fields for this configuration (:file:`ORCA2_OFF_v4.0.tar`) comes from a 2000 years long climatological simulation of ORCA2_ICE using ERA40 atmospheric forcing.
ln_linssh = .true.
) assuming that
model mesh is not varying in time and
it includes the bottom boundary layer parameterization (ln_trabbl = .true.
) that
requires the provision of BBL coefficients through sn_ubl
and sn_vbl
fields.ORCA2_OFF_PISCES
) or
a user defined set of tracers and source-sink terms with ln_my_trc = .true.
(and adaptation of ./src/TOP/MY_TRC
routines).In addition, the offline module (OFF) allows for the provision of further fields:
-
River runoff can be provided to TOP components by setting
ln_dynrnf = .true.
and by including an input datastream similarly to the following:sn_rnf = 'dyna_grid_T', 120, 'sorunoff' , .true., .true., 'yearly', '', '', ''
-
VVL dynamical fields, in the case input data were produced by a dyamical core using variable volume (
ln_linssh = .false.
) it is necessary to provide also diverce and E-P at before timestep by including input datastreams similarly to the followingsn_div = 'dyna_grid_T', 120, 'e3t' , .true., .true., 'yearly', '', '', '' sn_empb = 'dyna_grid_T', 120, 'sowaflupb', .true., .true., 'yearly', '', '', ''
More details can be found by inspecting the offline data manager in the routine :file:`./src/OFF/dtadyn.F90`.
ORCA2_SAS_ICE
More informations about SAS can be found in :doc:`NEMO manual <cite>`.
SPITZ12
SPITZ12
is a regional configuration around the Svalbard archipelago
at 1/12° of horizontal resolution and 75 vertical levels.
See :gmd:`Rousset et al. (2015) <8/2991/2015>` for more details.
This configuration references to year 2002, with atmospheric forcing provided every 2 hours using NCAR bulk formulae, while lateral boundary conditions for dynamical fields have 3 days time frequency.
References