Running NEMO on HECToR: creating new experiment data, verifying the output and visualising data

A typical NEMO run has a number of input and output files which vary depending on the particular model being solved. The input and output files used for the test configuration are summarised below:

• Input files
  • namelist - contains parameters which control the run, e.g. number of timestep, output frequency, which data to compute etc.
  • Various netCDF files which contain information required by the code.
• Output files
  • ocean.output General info on run
  • solver.stat Output from solver for each time step
  • time.step Timing info for each model time step
  • ice_evolu Information relating to sea-ice
  • date.file Contains info which gives the date range over which the model runs, e.g. O25-TST_1m_19580101_19580101_ for this example.
  • layout.dat Contains info relating to the layout used for this run.
  • *.nc - netCDF format, one file per processor

The number of netCDF (*.nc) output files is determined by the particular output files requested in the namelist and the number of processors on which NEMO is executed. For the test configuration, 7 sets of *.nc files are output with names of the form:-

O25-TST_1m_19580101_19580101_grid_T_0100.nc
O25-TST_1m_19580101_19580101_grid_U_0100.nc
O25-TST_1m_19580101_19580101_grid_V_0100.nc
O25-TST_1m_19580101_19580101_grid_W_0100.nc
O25-TST_1m_19580101_19580101_icemod_0100.nc
O25-TST_00000060_restart_0100.nc
O25-TST_00000060_restart_ice_0100.nc

Thus, if NEMO is executed on 221 processors then, on completion, a total of, 221*7 = 1547, *.nc files are generated by the run. The *grid*.nc and *icemod*.nc files contain model information for each time step. The *restart*.nc files are files which enable the model to be restarted from a particular point in model time.