1 Time transformations

• LOCTRANS:

  LOCTRANS requires one configuring line on which a time transformation, automatically performed below the call to oasis_put, should be indicated:

   # LOCTRANS operation
     $TRANSFORM
  

  
  where $TRANSFORM can be
  • INSTANT: no time transformation, the instantaneous field is transferred;
  • ACCUMUL: the field accumulated over the previous coupling period is exchanged (the accumulation is simply done over the arrays field_array provided as third argument to the oasis_put calls without any specific weighting);
  • AVERAGE: the field averaged over the previous coupling period is transferred (the average is simply done over the arrays field_array provided as third argument to the oasis_put calls without any specific weighting);
  • T_MIN: the minimum value of the field for each source grid point over the previous coupling period is transferred;
  • T_MAX: the maximum value of the field for each source grid point over the previous coupling period is transferred;
  • ONCE: UNUSED, not supported in OASIS3-MCT.

  Time transformations are now supported more generally than with previous versions of the coupler with use of the coupling restart file. The coupling restart file allows the partial time transformation at the end of the run, if any (e.g. if the AVERAGE period specified is longer than the run), to be saved at the end of a run for exact restart at the start of the next run. When LOCTRANS transformations are specified, the initial coupling restart file should not contain any LOCTRANS restart fields. For the following runs, it is mandatory that the coupling restart file contains LOCTRANS restart fields coherent with the current namcouple entries. For example, it will not be possible to restart a run with a multiple field entry in the namcouple with a coupling restart file created by a run not activating this multiple file option. This is the reason why it is now possible to specify a restart file name on the OUTPUT namcouple input line. Note that if there is no partial transformation to be saved, the restart file will still contain a restart field with 0 everywhere.