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 ne16pg3_t232. 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 DEBUG

  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 ne16pg3_t232 --compset B1850C_LTso --run-unsupported

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

    cd /glade/u/home/$USER/cases/b1850.length
    ./xmlchange PIO_DEBUG_LEVEL=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 6 months of model run. Remember that you have already run for 1 month.

Hint!

  1. 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 “5”

    ./xmlchange STOP_N=5

  1. Set INFO_DBUG to 1

    ./xmlchange PIO_DEBUG_LEVEL=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