# Sequential Mode in Ariane¶

Until now, we have entered only one input file into Ariane. Use Ariane’s sequential mode to enter multiple files.

## Input Files¶

The NetCDF files used as input must have the following format: prefix_number_suffix

If the file names do not follow this format, create symbolic links that do. Create this link by using the command ln -s [target file directory] [symbolic link name]

For example, you may consider:

• prefix = SalishSea_

• number = 01, 02, etc

• suffix = _grid_T.nc, _grid_U.nc, _grid_V.nc

Note: number must contain a constant digit number and its value must increase by one in chronological order. For example, file SalishSea_01_grid_T.nc contains tracers for November 1st and SalishSea_02_grid_T.nc contains tracers for November 2nd.

## Namelist: Modify Sections¶

First, let’s take a closer look at the parameters in the namelist sections. The parameter names are c_dir_X, c_prefix_X, ind0_X, indn_X, maxsize_X, and c_suffix_X where X is zo, me, te, sa for the ZONALCRT, MERIDCRT, TEMPERAT, and SALINITY sections, respectively.

### Input File Directory¶

c_dir_X is the directory with the symbolic links for the input files, the namelist, and the initial positions text file.

### New Input Filename¶

Previously, we have been entering the full filename, SalishSea_t_yyyymmdd_yyyymmdd_grid_T.nc, into c_prefix_X.

Now that we have formatted the filenames as prefix_number_suffix, c_prefix_me takes on the value of the prefix and c_suffix_me takes the value of suffix.

ind0_X is the number for the earliest input file and indn_X is the latest.

maxsize_X is the number of digits in number.

For example, the ZONALCRT section would look like the following for input files SalishSea_01_grid_U.nc and SalishSea_02_grid_U.nc :

&ZONALCRT
c_dir_zo ='/ocean/imachuca/MEOPAR/Ariane/results/drifter_compare/sequential/',
c_prefix_zo ='SalishSea_',
ind0_zo =01,
indn_zo =02,
maxsize_zo =2,
c_suffix_zo ='_grid_U.nc',
nc_var_zo ='vozocrtx',
nc_var_eivu ='NONE',
/


### Sequential Parameter¶

Under the ARIANE section in namelist, change key_sequential to TRUE.

## Namelist: Add Section¶

Add a SEQUENTIAL section in namelist. This section has one parameter, maxcycles. We recommend the value of this parameter to be 1 since this tells Ariane to stop generating trajectory points once it has run out of input data.

### Sequential¶

&SEQUENTIAL
maxcycles =1,
/


## Results¶

The results produced for the example above: