4. Initializing the model state¶
4.1. Temperature and salinity distribution¶
Todo
put in link for namelist &init_ts_nml for Temperature and salinity initialization
4.2. Restart control¶
As a POP calculation proceeds, restart files are produced at intervals
of simulated time specified by the parameter restart_freq in
namelist restart_nml. The root of the restart filename is given by
the restart_outfile variable. The actual full filename will be
restart_outfile.runid.suffix where suffix is a number that depends
on restart_freq_opt. If this option is ‘nyear’, ‘nmonth’ or ‘nday’
suffix will be the calendar day in yyyymmdd. If the option is ‘nstep’,
suffix will be the current step number. In the unlikely case that the
user chooses ‘nhour’ or ‘nsecond’, suffix will be yyyymmdd.[hh,sssss]
where hh and sssss denote the current hour or seconds in the current
day.
Todo
put in lnk for namelist &restart_nml for Restart file namelist
In addition to these named restart files, additional restart files may
be written using the even/odd convention. If leven_odd is set to
.true., the model will write restart files every
even_odd_freq steps. These files will be named
restart_outfile.runid.even,odd where the code alternately writes to
an even or odd file. Any previous file of the same name will be
overwritten. This capability is particularly useful for backup in case
the simulation terminates prematurely; it provides restart capability
without needing to keep many named restart files present in the file
system. The model writes alternately to each of two such files so that
if an error occurs while writing one restart file, the other restart
file will still (presumably) be all right.
Restart files contain only the minimum information required to restart
the model exactly, so that the results are the same after a restart as
would have been the case had no restart been done. This means that two
time-levels (n-1 and n) of the prognostic variables (PT, S, U, V and H)
must be saved in 64-bit precision. The restart format is governed by the
restart_fmt option. Note that using netCDF for restarts on machines
that do not use the IEEE binary format standard will result in restart
files that are not exact due to internal conversion by the netCDF
library. This will prevent exact reproducibility on such machines.
Binary format is therefore highly recommended for restart files.