Exercise 1: Modify run length

Exercise 1: Modify run length#

Exercise: Modify the env_run.xml file

Part I:
Create a new fully coupled case named “b1850.length” from the 1850 climate conditions with a resolution of f19_g17. Increase the amount of standard output produced by the model for debugging. Run for 1 month.

Hint!

  1. Which variable controls the amount of standard output for debugging? We can use partial query to find out:

    ./xmlquery -p DBUG

  1. Use xmlchange to modify env_run.xml

  2. Make sure to update the walltime to match the run length.

Click here for the solution to Part I

From the SRCROOT (/glade/u/home/$USER/code/my_cesm_code) directory, create your case:

    cd /glade/u/home/$USER/code/my_cesm_code/cime/scripts
    ./create_newcase --case /glade/u/home/$USER/cases/b1850.length --res f19_g17 --compset B1850

In your case directory, change debugging levels and set runtime variables:

    cd /glade/u/home/$USER/cases/b1850.length
    ./xmlchange INFO_DBUG=2,STOP_N=1,STOP_OPTION=nmonths
    ./xmlchange --subgroup case.run JOB_WALLCLOCK_TIME=2:00:00

Check CaseStatus, you’ll see that the changes were automatically documented.

Carry on to setup, build and submit the run:

      ./case.setup 
      qcmd -- ./case.build
      ./case.submit

Remember that qcmd is used on Derecho only.

Exercise: Modify the env_run.xml file

Part II: Do part II only after Part I has finished running.
Change the debug level back to 1. Expand Part I to produce a total of 12 months of model run. Remember that you have already run for 1 month.

Hint!

  1. Which variable controls the amount of standard output for debugging? We can use partial query to find out:

    ./xmlquery -p DBUG

  1. Use xmlchange to modify env_run.xml

  2. Make sure to update the walltime to match the run length.

  3. For Part II, how to tell the model that this run continues from the previously finished run of 1 month?

Click here for the solution to Part II

  1. To continue the run, set CONTINUE_RUN to TRUE

    cd /glade/u/home/$USER/cases/b1850.length
    ./xmlchange CONTINUE_RUN=TRUE

  1. Keep STOP_OPTION as “nmonths”

  2. Set STOP_N to “11”

    ./xmlchange STOP_N=11

  1. Set INFO_DBUG to 1

    ./xmlchange INFO_DBUG=1

  1. (optional) Change queue if submitting after the lab session

    ./xmlchange JOB_QUEUE=main

  1. Change wallclock time to use the maximum of the allowed wallclock on Derecho:

    ./xmlchange --subgroup case.run JOB_WALLCLOCK_TIME=12:00:00

  1. Submit (./case.submit) from your b1850.length case directory:

    ./case.submit