FAQ - adcroft/MOM6-examples GitHub Wiki

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  • Unclassifiable statement

When compiling FMS if you see

.../src/FMS/diag_manager/diag_axis.F90:1517.4:

    associate (axis=>Axes(id))
    1
Error: Unclassifiable statement at (1)

then you are likely using an older version of gcc. The FMS code now uses Fortran 2003 extensions that need newer versions of compilers (gcc 4.8 and 5.3 are known to work).

  • No such FMS subroutine

If you see an compiler error such as

Error: There is no specific subroutine for the generic 'read_data' at ...

it means the FMS sub-module is not at the correct commit. To remedy:

cd MOM6-examples/ git submodule update src/FMS

Run

  • MPP_DO_GLOBAL_FIELD user stack overflow

The mpp I/O software layer needs a big stack. Try increasing the parameter domains_stack_size in the fms_nml namelist. e.g.

&fms_nml
       domains_stack_size = 9552960
/
  • NETCDF ERROR: No such or directory File=RESTART/MOM.res.nc

This happens when the model tries to write the restart file to a directory that does not exist. Create the directory RESTART/ before running.

  • How do I restart the model with a different layout?

First, if your restart files from the last model segment are not combined, then you need to do this (you may have more than one MOM restart file depending on the size of your grid)

To combine restarts, use the mppnccombine tool, e.g.

mppnccombine -f -64 MOM.res.nc
...

The input_filename parameter needs to change from "n" to "r" in order to pickup from a restart

&MOM_input_nml
         output_directory = '.',
         input_filename = 'r'

Also, make sure that "INPUT/coupler.res" is has the correct timestamp, since this is what will be used to determine the current model time when using the FMS MOM6/SIS2 coupler, e.g.

      2        (Calendar: no_calendar=0, thirty_day_months=1, julian=2, gregorian=3, noleap=4)
      1900     1     1     0     0     0        Model start time:   year, month, day, hour, minute, second
      1901     1     1     0     0     0        Current model time: year, month, day, hour, minute, second