Running EnOI data assimilation code requires an configuration file as input (*assim.input in your distribution package*). This file looks like
this and is split below for a basic recap of the various settings.

... WRITE YOUR COMMENTS BELOW... Ensemble description : copie du persian pour tests amont version polychromatique test toutes perturbations sauf OBC M2 M4 ... DO NOT REMOVE NEXT LINE... end comments

*header section:* for user's convenience only

16 ! twin experiment option flag (NONE|#)

*run mode: *sets the run mode. Alternates are **DRY** for a dry-run mode, **#** for a twin-experiment (**#** is the control run taken from the ensemble runs) and **NONE** for a realistic experiment.

M2 M4 ! Tidal constituent list

*tidal constituents list:* sets the list of tidal constituent(s) to be processed. Polychromatic coupling is applied unless **NO_COUPLING** code building.

../../data/persian-gulf.nei ! Ensemble mesh file

*mesh file: *sets the common mesh file name for all ensemble runs.

../../data/topo.s2r ! Ensemble topo file

*topography file:* sets the topography file name.

20 ! Number of members in ensemble

*ensemble size:* sets the ensemble dimension.

../../ensemble_topo-DGP1xLGP2/membre ! Ensemble root name

*ensemble runs rot name:* sets the ensemble runs archiving directory root name.

WAVE.spectral.nc ! Ensemble elevation solutions naming convention WAVE.spectral.nc ! Ensemble velocities solutions naming convention

*naming conventions:* sets the naming conventions for ensemble runs solutions in tidal elevations and velocities. **WAVE** and/or **ITERATION** are respectively replaced by the tidal constituents and harmonic analysis solution processed.

09 ! Analysis number

*harmonic analysis:* sets the analysis solution to be used for ensemble runs.

DGP1xLGP2 ! FE description

*finite elements description:* sets the finite elements pair describing ensemble runs. Available pairs are **LGP0xLGP1**, **LGP1xLGP1**, **DGP1xLGP2**.

../../data/persian-gulf.nei ! Prior mesh file

*mesh file: *sets the mesh file name for prior solution.

../../spectral-gridded-DGP1xLGP2/ ! Prior solution ("path"|NONE)

*prior solution:* sets the path to prior solution archiving directory.

WAVE.spectral.nc ! Prior solution elevation naming convention WAVE.spectral.nc ! Prior solution velocity naming convention

*naming conventions:* sets the naming conventions for prior solution in tidal elevations and velocities. **WAVE** and/or **ITERATION** are respectively replaced by the tidal constituents and harmonic analysis solution processed.

09 ! Analysis number for prior solution

*harmonic analysis:* sets the analysis solution to be used for prior solution.

DGP1xLGP2 ! FE description for prior solution

*finite elements description: *sets the finite elements pair describing ensemble runs. Available pairs are **LGP0xLGP1**, **LGP1xLGP1**, **DGP1xLGP2**.

../../obs/c-error/M2.obs ! Observation file wave 1../../obs/c-error/M4.obs ! Observation file wave N

*observation file(s):* sets the observation file(s) corresponding to the tidal constituents to be processed.

NONE ../obs/test.plg ! Filter polygone (file name| NONE )

*polygone file:* sets the polygone file defining the geographical area where observations are selected. NONE discards the option.

NONE geo-toponyms-18.grd ! Filter toponyms map (file name| NONE )

*toponyms file:* sets the toponyms map file defining the geographical area where observations are selected. NONE discards the option.

0 ! Observation additional error flag (0|1)0.05 0 ! Observation additional errors [units: m and °]

*additional error option: *allows**(1)**/denies**(0)** an additional error in amplitude and phase lag to all observations.

0 ! Observation selection flag (0|1)0.9 ! Observation selection correlation20 ! Observation selection distance [km]50 ! Observation selection tide constants similar at N percent

*observation selection option:* allows**(1)**/denies**(0)** observations are restricted to correlation, distance and likeliness parameter values.

8000 ! Correlation radius maximum length(en km) R-LINEAR ! Covariance function (MODEL NAME | NONE)

*observations decorrelation:* sets the observation decorrelation length and model. Available models are linear (**R-LINEAR**, **R-STEP**), sinusoidal (**R-COSINE**), exponential (**R-EXPONENTIAL**, **R-EXPONENTIAL-TRUNCATED**), spheric (**R-SPHERICAL**), gaussian (**R-GAUSSIAN****, R-GAUSSIAN-TRUNCATED**, **R-GAUSSIAN-DAMPED**), polynomial-exponential based from *Arhan et Colin de Verdière, JPO, 1985* (**R-ARHAN85**). **NONE** or a negative distance discards the option.

1 ! Model units scale factor (default value is 1)

*model units scaling: *sets the model units scale factor

3.2 ! Model error scale factor (default value is 1)

*model error scaling: *sets the model error scale factor

1 ! Currents assimilation flag (0|1)

*currents analysis option: *allows**(1)**/denies**(0)** the use of model tidal velocities covariance information.

1 ! Compute penalty function (0|1)

*penalty function option:* allows**(1)**/denies**(0)** the computation of observation and prior/analysis model penalty function.

CHOLESKY ! Solver Type

*solver type: *sets the algorithm for assimilation system resolution and inverse computation of matrices. Alternates are **CHOLESKY** or **LU**.

1 ! Save elevation correction (0|1)1 ! Save currents correction (0|1)

*analysis increments save options:* allows**(1)**/denies**(0)** saving analysis increments for tidal elevation and velocities.

1 ! Save ensemble mean (0|1) 1 ! Save ensemble variance (0|1)

*ensemble statistice save options:* allows**(1)**/denies**(0)** saving ensemble means and variances for tidal elevation and velocities.

1 ! Save assimilated observations (selected.obs) (0|1)

*observations save option:* allows**(1)**/denies**(0)** saving observations used for the data assimilation run.

0 ! Save assimilation matrices (0|1)

*matrix save option:* allows**(1)**/denies**(0)** saving covariances matrices for both model and observations errors.

0 ! Save observations domain of influence (ASCII only, doi.s2r) (0|1)

*domain of influence save option:* allows**(1)**/denies**(0)** saving individual observation domain of influence.

0 ! Compress members solution (0|1)

*archiving ensemble mode:* allows**(1)**/denies**(0)** the use of compressed archives for ensemble runs solutions

1 ! Internal check mode (0|1)

*internal check option:* allows**(1 or more)**/denies**(0)** data assimilation run internal checks.

1 ! Additional diagnostic mode (0|1)

*diagnostic mode option:* allows**(1)**/denies**(0)** additional run diagnostics.

1 ! Verbose mode (0|1)

*verbose mode option:* allows**(1)**/denies**(0)** data assimilation run messages

2 ! Parallel mode CPUs (NONE | N)

*parallel mode:* sets the number of CPU(s) to be requested for parallel mode data assimilation run, provided a parallel code building.