Exercise 1: Modify run length

Exercise 1: Modify run length#

Exercise: Modify the env_run.xml file

Part I:
Create a new fully coupled startup case named “b.day2.1” 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.

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 38 months of model run. Remember that you have already run for 1 month. You should submit this at the end of the day so that it will (hopefully) run overnight and be available the following day. You can continue with Exercise 2-3 and submit the run later.

Hint!

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

    ./xmlquery -p DBUG

Use xmlchange to modify env_run.xml
Make sure to update the walltime to match the run length.
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 I

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

    cd /glade/work/$USER/code/my_cesm_code/cime/scripts
    ./create_newcase --case /glade/work/$USER/cases/b.day2.1 --res f19_g17 --compset B1850

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

    cd /glade/work/$USER/cases/b.day2.1
    ./xmlchange INFO_DBUG=2,STOP_N=3,STOP_OPTION=nmonths
    ./xmlchange --subgroup case.run JOB_WALLCLOCK_TIME=2:00:00

Remember to manually update your README.case file to document your changes.

Carry on to setup, build and submit the run:

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

Remember that qcmd is used on Cheyenne only.

Click here for the solution to Part II

1. To continue the run, set `CONTINUE_RUN` to `TRUE`

    ./xmlchange CONTINUE_RUN=TRUE

2. Keep `STOP_OPTION` as "nmonths”
3. Set `STOP_N` to “37”

    ./xmlchange STOP_N=37

4. Set INFO_DBUG to 1

    ./xmlchange INFO_DBUG=1

5. Change wallclock time to use the maximum of the allowed wallclock on Cheyenne:

    ./xmlchange --subgroup case.run JOB_WALLCLOCK_TIME=12:00:00
    ./xmlchange --subgroup case.st_archive JOB_WALLCLOCK_TIME=6:00:00

6. Submit (./case.submit) from your b.day2.1 case directory:

    ./case.submit