Setting up a branch or hybrid run

The section setting the case initialization discussed starting a new case as a branch run or hybrid run by using data from a previous run. First you need to create a new case. Assume that $CCSMROOT is set to /user/ccsmroot and that $EXEROOT is /ptmp/$user/b40.B2000p. Finally, assume that the branch or hybrid run is being carried out on NCAR's IBM system, yellowstone.


> cd /user/ccsmroot/scripts
> create_newcase -case ~/cesm1/b40.B2000p \
                 -compset B_2000 \ 
                 -res 0.9x1.25_gx1v6 \
                 -mach yellowstone 
> cd ~/cesm1/b40.B2000p

For a branch run, modify env_conf.xml to branch from b40.B2000 at year 0001-02-01.


> xmlchange -file env_conf.xml -id RUN_TYPE    -val branch
> xmlchange -file env_conf.xml -id RUN_REFCASE -val b40.B2000
> xmlchange -file env_conf.xml -id RUN_REFDATE -val 0001-02-01

For a hybrid run, modify env_conf.xml to start up from b40.B2000 at year 0001-02-01.


> xmlchange -file env_conf.xml -id RUN_TYPE    -val hybrid
> xmlchange -file env_conf.xml -id RUN_REFCASE -val b40.B2000
> xmlchange -file env_conf.xml -id RUN_REFDATE -val 0001-02-01

For a branch run, env_conf.xml for b40.B2000p should be identical to b40.B2000, except for the $RUN_TYPE setting. In addition, any modifications introduced into ~/cesm1/b40.B2000/Buildconf/$component.buildnml.csh, should be re-introduced into b40.B2000p.

Configure and build the case executable.


> configure -case 
> b40.B200p.yellowstone.build

Prestage the necessary restart/initial data in $RUNROOT (assumed to be /ptmp/$user/b40.B2000p/run). Note that /ptmp/$user/b40.B2000p/run was created during the build. Assume that the restart/initial data is on the NCAR mass store.


> cd /ptmp/$user/b40.B2000br/run
> hsi "cd /CCSM/csm/b40.B2000/rest/0001-02-01-00000; get *" 

It is assumed that you already have a valid load-balanced scenario. Go back to the case directory, set the job to run 12 model months, use an editor to change the time limit in the run file to accommodate a 12-month run, then submit the job.


> ~/cesm1/b40.B2000p
> xmlchange -file env_run.xml -id STOP_OPTION -val nmonths
> xmlchange -file env_run.xml -id STOP_N -val 12
> # use an editor to change b40.B2000.yellowstone.run "#BSUB -W 1:30" to "#BSUB -W 6:00"
> bsub < b40.B2000p.yellowstone.run

Verify that the run succeeded.


> grep "SUCCESSFUL TERMINATION" poe.stdout.*

Change the run to a continuation run. Set it to resubmit itself 10 times so that it will run a total of 11 years (including the initial year), then resubmit the case.


> xmlchange -file env_run.xml -id CONTINUE_RUN -val TRUE
> xmlchange -file env_run.xml -id RESUMIT -val 10
> bsub < b40.B2000p.yellowstone.run