Setting up a branch or hybrid run

A branch or hybrid run uses initialization data from a previous run. Here is an example in which a valid load-balanced scenario is assumed. This requires the Setting up a multi-year run to have been ran and completed successfully.

1. The first step in setting up a branch or hybrid run is to create a new case.

   ./scripts/create_newcase --case ~/BRANCH_HYBRID --compset B1850 --res f09_g17
   cd ~/BRANCH_HYBRID
   

2. Now to setup the branch/hybrid starting from year 0001-02-01 of the previous run.

   For a branch run, use the following xmlchange commands to make NEW_CASE be a branch off of EXAMPLE_CASE at year 0001-02-01.

   ./xmlchange RUN_TYPE=branch
   ./xmlchange RUN_REFCASE=EXAMPLE_CASE
   ./xmlchange RUN_REFDATE=0001-02-01
   

   Note

   For a branch run, the env_run.xml file for NEW_CASE should be identical to the file for EXAMPLE_CASE except for the $RUN_TYPE setting. Also, modifications introduced into user_nl_ files in EXAMPLE_CASE should be reintroduced in NEW_CASE.

   For a hybrid run, use the following xmlchange command to start NEW_CASE from EXAMPLE_CASE at year 0001-02-01.

   ./xmlchange RUN_TYPE=hybrid
   ./xmlchange RUN_REFCASE=EXAMPLE_CASE
   ./xmlchange RUN_REFDATE=0001-02-01
   

4. Next, set up and build the case executable.

   ./case.setup
   ./case.build
   

5. Pre-stage the necessary restart/initial data in $RUNDIR. For this example the restart files are assumed to be in $DOUT_S_ROOT/EXAMPLE_CASE/rest/0001-02-01-00000.

   cp $DOUT_S_ROOT/EXAMPLE_CASE/rest/0001-02-01-00000/* $RUNDIR/
   

   It is assumed that you already have a valid load-balanced scenario. Set the job to run 12 model months, and submit the job.

   ./xmlchange STOP_OPTION=nmonths
   ./xmlchange STOP_N=12
   ./xmlchange JOB_WALLCLOCK_TIME=06:00
   ./case.submit
   

6. Make sure the run succeeded and and then change the run to resubmit 10 times so it will run a total of 11 years (including the initial year), then resubmit the case.

   ./xmlchange CONTINUE_RUN=TRUE
   ./xmlchange RESUBMIT=10
   ./case.submit
   

   Note

   By default only a single job will be submitted at a time, to change this use ./case.submit --resubmit-immediate which will submit all jobs at once using batch dependencies.